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The Ketogenic Diet and Its Effects on Endurance Performance

You often hear about the Ketogenic (keto) diet when people are trying to lose weight; often times a significant amount of it. People will often boast about how they lost 10-15 lbs within the first month on the keto diet. For those who are accustomed to eating high-carbohydrate diets, this is normal and perhaps even expected. This is mostly the result of the release of excess glycogen and water that carbs often hold onto. Without the carbs, less water and glycogen is stored in the skeletal muscle tissue. 

But how does this affect one’s endurance performance? Is this an effective dieting methodology to utilize to prepare for competition? Is it an effective nutritional intervention whatsoever?


It’s Not So Simple

There are several studies out there that support the notion that it doesn’t make a difference where it counts. You’ll figure out what I mean by that in a minute.

In a study that tested ultra-marathoners and triathletes, they found out that after performing both a maximally graded incline treadmill test along with a 180 minute submaximal run at 64% of VO2 max, there were no differences between the high-carbohydrate and low-carbohydrate diet groups in the level of muscle glycogen in the muscle after exercise and even 2 hours post-workout [1]. 

Now, this occurred while the energy utilization completely differed between the two groups. In the low-carb group, fat oxidation (the process of fat being released into the bloodstream to be burned for use) was over 2x higher than in the high-carb group.

Okay, well they may have performed similarly, but the low-carb group lost more fat, right? Well again…

It’s not so simple!

Keto Diet

Effects on Body Composition

You’d probably be surprised to find out that following a low-carb keto diet won’t make you lose fat any faster either! To this date, all studies comparing keto diets to standard moderate carb diets, with protein and calories equal between the groups, have shown no fat loss advantage [2]. Researchers postulate that favorable fat loss advantages are often seen in those who follow the keto diet because they also inadvertently increase their protein intake [3].

However, there does seem to be an advantage that the keto diet has that standard diets don’t; it effects appetite regulation. Study after study has shown that individuals often unconsciously reduce their calorie intake when following a strict keto diet, as dietary fats have a greater effect on hunger than carbohydrates do, independent of protein consumption [4]. Because of this, it may be a smart move to utilize this type of diet if you constantly battle with hunger while dieting.  

Should You Even Bother?

Well. that’s a tough question. Because there’s actually some compelling research out there to prove that utilizing it to an extent may enhance performance. 

Without getting too deep into the physiological mechanisms of keto, basically, keto uses an energy source called ketones (once you’re adapted to the diet) instead of glucose for energy. Glucose, when converted to glycogen, is what is normally used for energy from carbohydrate. However, in its absence, it utilizes the next best thing; ketones, also known as ketone bodies. 

These ketones have become available in many sports supplements in the form of salts; often referred to as exogenous ketones. Researchers believe that while utilizing a moderate carb diet, supplementing with these salts may help to increase glycogen replenishment after exercise and help to promote skeletal muscle recovery [5]. In this scenario, we get the “best of both worlds” and we theoretically have energy coming from multiple sources, increasing our efficiency and output. 

But don’t get too excited just yet. These keto supplements are still relatively in their infancy stages on the supplement market. Therefore, more evidence is needed in order to make this a more definitive claim. 

Keto Diet

It Just Doesn’t Seem Meant To Be…For Now

With the current research we have out right now (which is surprisingly limited in athletes), the general trend seems to fall towards a negative impact in several training variables. These include heart rate, level of perceived effort, and overall training quality [6]. This seems especially evident when performing at higher levels of intensity, as one reaches closer to the muscle glycogen utilization threshold, where carbohydrate loading techniques would often be employed.

On the other side of the coin, there’s no one-size-fits-all answer here either. Some researchers have trouble understanding why some people are “high-responders” and “low-responders” to the keto diet. For example, a few of the individuals that were a part of a group of ultramarathoners appeared to perform better while on the keto diet. Researchers believe this to be because ultramarathons are more slowly paced than standard marathons, they rely more on fat stores, therefore, making it the superior fuel source [1]. But again, like with all things in research, this necessitates further examination. 

The Bottom Line

I hate to leave you all like this, but that is what I must do. I must leave you with an inconclusive ending.

There’s still much research to be done in this field. There simply haven’t been enough tests conducted and hypothesis’ tested in order to get an in-depth grasp of keto’s mechanisms on performance. But for now, it seems to be leading in the direction that carbs are still king. 

You may hear even more conflicting evidence in places such as social media, with advocates touting how great it is for performance. But remember, what works for them may not work for you. Hey, some people have actually performed better with it. Sometimes, you must treat yourself as your own test “subject” in order to see how these things affect you personally. Therefore, at least you can give yourself some data to work with!

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References

  1. Volek, J. S., Freidenreich, D. J., Saenz, C., Kunces, L. J., Creighton, B. C., Bartley, J. M., . . . Phinney, S. D. (2016). Metabolic characteristics of keto-adapted ultra-endurance runners. Metabolism, 65(3), 100-110. doi:10.1016/j.metabol.2015.10.028
  2. Aragon, A. A., Schoenfeld, B. J., Wildman, R., Kleiner, S., Vandusseldorp, T., Taylor, L., . . . Antonio, J. (2017). International society of sports nutrition position stand: Diets and body composition. Journal of the International Society of Sports Nutrition, 14(1). doi:10.1186/s12970-017-0174-y
  3. Soenen, S., Bonomi, A. G., Lemmens, S. G., Scholte, J., Thijssen, M. A., Berkum, F. V., & Westerterp-Plantenga, M. S. (2012). Relatively high-protein or ‘low-carb’ energy-restricted diets for body weight loss and body weight maintenance? Physiology & Behavior, 107(3), 374-380. doi:10.1016/j.physbeh.2012.08.004
  4. Sumithran, P., Prendergast, L. A., Delbridge, E., Purcell, K., Shulkes, A., Kriketos, A., & Proietto, J. (2013). Ketosis and appetite-mediating nutrients and hormones after weight loss. European Journal of Clinical Nutrition, 67(7), 759-764. doi:10.1038/ejcn.2013.90
  5. Evans, M., Cogan, K. E., & Egan, B. (2016). Metabolism of ketone bodies during exercise and training: Physiological basis for exogenous supplementation. The Journal of Physiology, 595(9), 2857-2871. doi:10.1113/jp273185
  6. Burke, L. M., & Hawley, J. A. (2002). Effects of short-term fat adaptation on metabolism and performance of prolonged exercise. Medicine & Science in Sports & Exercise,34(9), 1492-1498. doi:10.1097/00005768-200209000-00015

Understanding FTP: VLa Max vs. Vo2 Max

Realizing your full potential, being the best you can be—it’s something many people strive for. It doesn’t matter if it’s in your career, relationship, or favorite video game. Trying to become the best you can be is universally understood. In sport—it’s the main objective. It doesn’t matter what you play, the number one goal is always the same. To get better. 

Unfortunately, the human body, our physiology, isn’t entirely understood. New theories and methods are endlessly tested to find the ultimate equation to maximize athletic performance. The pieces of the puzzle aren’t all in place—but it’s coming together. The picture is becoming clearer. 

We understand the general principals governing how our bodies work. This allows us to create effective programs and workouts, but we still don’t know enough about individual variability to address the unique training needs of every person. 

The dynamic relationship of our energy systems (anaerobic and aerobic for the sake of this article) is a good example of something we don’t entirely understand. The research is still underway. But, luckily we know enough to move us in the right direction. 

In endurance events, it’s understood that our Vo2max is an indicator of how well you will perform. But, what if someone has the same Vo2max as you – who’s gonna win?

Correct – It depends on other factors. Good job. 

The sections below outline the relationship between the two main contributors to endurance performance—aerobic capacity (Vo2max) and anaerobic capacity (VLamax).

FTP, VLa Max, VO2 Max

What are Vo2max and VLamax?

Vo2max (ml/kg/min): 

This is aerobic capacity. Vo2max, or maximal oxygen consumption, refers to the amount of oxygen someone can use during max effort exercise. This is widely considered the gold standard for evaluating cardiorespiratory fitness.

VLamax (mmol/s/l): 

This is anaerobic capacity, or the maximum rate of energy production by the glycolytic system. It is sometimes designated by the term VLamax or maximum production of lactate. In reality this is the maximum rate of production of pyruvate and lactate but since lactate is what is measured “La” has been used for this term. Clear as mud, right?

You’ll remember from a recent article about the Sweet Spot vs. Zone 2 debate in which I detail the change in lactate production from aerobic to anaerobic energy production:

In exercise where lots of oxygen is present (aerobic) your body will produce more pyruvate and less lactate. When you continue to push yourself into the higher power zones and above your lactate threshold, oxygen levels in the cells will decrease and you will go into anaerobic energy production, thus producing increased lactate and decreased pyruvate.  Continue to push harder and the levels of lactate produced will continue to increase while pyruvate levels decrease. I.e. the fuel ‘mixture’ of fat (pyruvate) to carbohydrate (lactate) changes as an athlete works closer to their individual lactate threshold.

So, we’re always producing pyruvate and lactate, but as the oxygen levels in the cells decrease, i.e. you start to push the pedals harder, the body will convert more pyruvate to lactate and your lactate concentrations will increase. Since we can’t easily measure pyruvate, but can lactate, we have VLa Max… Capeesh?

Why Does it Matter for Performance?

When it comes down to it, Vo2max and VLamax are comparisons of your aerobic and anaerobic systems. The relative strengths of these two systems will determine your performance capabilities.

As an endurance athlete, the %Vo2 you can maintain is directly related to how strong your anaerobic energy system is. The stronger your anaerobic system is, the more it will contribute at any given intensity. This makes you reach threshold faster—reducing your endurance capacity. “Shayne, this is the most confusing article EVER, dude”. Hang on a sec, here’s are example…

Example – Think about two cyclists with the same aerobic capacity; Let’s say 55ml/kg/min, and identical lactate buffering abilities. Cyclist 1 has a VLa of .7 mmol/s/l and cyclist 2 has a VLa of .2mmol/s/l. During exercise, cyclist 1 will experience blood lactate accumulation faster than cyclist 2 because of their higher VLa. As a result cyclist 1 will fatigue at a lower percentage of their Vo2max than cyclist 2. HOWEVER, cyclist 1 will crush cyclist 2 in a sprint, or short steep hill climb.

So, to K.I.S.S. – IF you need to produce lots of power for a short duration, THEN having a higher VLa is desired, BUT IF you need to go long and keep power down forever, THEN having a lower VLa is desired.

How you train will have a significant impact on how your energy systems adapt and interact. Obviously the way your systems function can be improved—that’s why you train. 

But what’s the right balance of training to optimize your adaptation?

No matter what event you’re training for—you will rely on all of your energy systems. 

“Designing a workout to induce just one specific biological adaptation is impossible. Most of the time there is a major effect (class effect) coupled with minor effects whether desired or not.” 


– Olbrecht, “The science of winning”
FTP, VLa Max, VO2 Max.

What Does it Mean for Training?

A basic principle of physiology that’s important to understand when considering how to improve your performance is the dimmer switch effect. A dimmer switch allows you to adjust it across a spectrum of levels based on your needs. The energy systems of your body operate in a similar way. 

See, your body uses three different systems to get energy (yes, I am combining the 2 CP systems, nerd!). All three are always on but the amount each contributes depends on the energy demands of activity. Each one supplies energy at a different rate and a different quantity. The fastest system supplies the least amount of energy; while the slowest system produces the most- this is your aerobic system. Your anaerobic system is somewhere in the middle.

Example:

Let’s use fireworks…so, your Creatine Phosphate (CP) system is like a firecracker producing a lot of energy, but for a very short amount of time. Next up is your anaerobic system (VLa) which is more like a sparkler producing a fair amount of energy, but for just a few minutes. Lastly is your aerobic system (VO2) which is like a lighter, producing enough energy to get the job done, and will continue to burn low and slow as long as there is fuel in the tank.

Huh, huh, huh huh FIRE! FIRE!

Sorry, I had to… Back on topic, Shayne! C’mon, man!

Low intensity exercise requires less energy allowing us to use our slowest, most efficient energy system with only small contributions from the other two. As your exercise intensity changes, the contribution ratio of each energy system also changes.  More intensity means more energy in less time. Your aerobic system will start to contribute less as your anaerobic system turns up. 

The dominant system or systems, the ones that are “stressed”, will experience training adaptation. Any system that isn’t needed will not be trained and will experience a decrease in functional capacity. 

How you train changes the amount each system will adapt. By emphasizing endurance training you’re going to up regulate aerobic contributions and down regulate anaerobic contributions—and vice versa. Focusing on speed and intensity will improve anaerobic functioning but limit your aerobic system. 

To find the right balance, you need to strategically vary your training sessions. Identify your training goals to help you determine the types of sessions to emphasize in your programming. 

If you’re training for endurance events the vast majority of your training should emphasize your aerobic energy system—around 80% of all training. The results of this are two-fold—your anaerobic system gets weaker and your aerobic system gets stronger.

Nutritional Suggestions

As an athlete with a higher anaerobic contribution, you should consume more carbohydrate before and during exercise. If you rely more on carbs and glycolysis, your blood sugar levels are going to decrease more quickly. During competition using a carbohydrate supplement will help maintain your blood sugar.

Another word of advice, if you have a very high intensity workout planned for the day, make sure you’re eating a carbohydrate-rich meal before and after your workout. This will ensure you have enough glucose to get through the workout, as well as replenish glycogen stores afterwards.

Regular dietary habits can also impact substrate use during exercise. If you have a high-fat diet, your body promotes systems that use fat more than carbohydrate. During exercise this translates to less glucose use and longer workouts. So, if you are trying to improve your aerobic capacity, eating more fat and less carbohydrate throughout the day, as well as doing some workouts fasted is a way to ‘bio-hack’ the system and get you greater results in less time.

FTP, VLa Max, VO2 Max

Conclusion

Properly adjusting training intensities to fit your overall training goals will result in an overall more effective program. While there are some nutritional suggestions, our performance abilities will be reflected largely by our choice in training. Make sure you’re applying Specificity and Progressive Overload to whatever system/s you’re trying to improve. Lastly, as one system becomes up-regulated (improves), the other will become down-regulated (worsen), and there are just a few genetic ‘freaks’ that are good at everything. If you are struggling with moving up in the ranks, you may want to adjust your training to further improve your strengths, and change what events / races you want to ‘peak’ for… Or maybe you want to try and improve your weaknesses instead… We can’t lose the art of coaching in all this ‘sciencey’ stuff after all!

Improving Anaerobic Threshold (AT) / FTP

Athletes reach anaerobic threshold (AT) due to their muscles inability to keep pace with the energy demands of activity. When our muscles can no longer meet these demands hydrogen ions begin to accumulate, increasing the acidity within the muscles, and impairing the muscles’ ability to perform, i.e. you get DROPPED. This can happen due to either a lack of available oxygen, or a lack of mitochondrial ability. Through increases in our ability to deliver oxygen and mitochondrial activity, we can increase the muscle’s ability to produce energy. This can be accomplished through the improvement of at least two different physiological variables—increased mitochondrial density and angiogenesis.

Increases in Mitochondrial Density

Our mitochondria, as you probably know from high school biology, are known as:

The powerhouse of the cell.

-Every biology teacher, EVER.
Anaerobic Threshold, FTP.

This means they’re responsible for producing a vast majority of the energy (ATP) we need. This is accomplished through our electron transport chain or ETC. The ETC is located along the walls of the mitochondria and uses hydrogen ions (H) to synthesize ATP. After creating ATP, the H ions need to be removed from the mitochondria—this is where oxygen comes into play. Oxygen combines with two hydrogen ions to form water.

Now these same hydrogen ions can also play a role in the buildup of lactate if the ETC gets “backed up”. The ETC gets backed up when oxygen isn’t present to accept hydrogen ions at the end of the process, i.e. your body enters anaerobic metabolism. When hydrogen ions can’t be moved through the ETC, they combine with pyruvate to form lactate. This lactate formation helps slow the increase of acidity in the muscles. The lactate is shipped off to other parts of the body to be re-purposed. To increase the capacity of a muscle, it must be able to process more hydrogen. This electron transport system respiratory state increases (by 25%) much more in response to HIIT training, whereas typical endurance training shows much less improvement, i.e. a non-significant 9% increase (2). So, if you struggle with repeated hard surges, or struggle with recovering quickly after a very hard effort, your ETC is becoming “backed up” too quickly… More HIIT training for you!

Promoting Angiogenesis

Angiogenesis is the formation of new vasculature due to hormonal and mechanical related signaling.

The mechanisms by which this process occurs are not entirely understood but have been observed after exercise training. As previously mentioned, oxygen delivery is a key component in mitochondrial functioning due to it’s role in the electron transport chain. Without oxygen the ETC can’t function. Oxygen is delivered to working muscle, and subsequently the ETC, through our vasculature. When we breathe, oxygen defuses from our lungs into our bloodstream and makes its way through the body. As it travels through the bloodstream oxygen diffuses into working muscle, allowing it to be used for hydrogen acceptance. Theoretically, if more oxygen can be delivered to the working muscles, then the ETC can function at a greater capacity, delaying the onset of anaerobic threshold. So if the capillary surface area interacting with muscles increases more oxygen will be able to enter the cells.

Research shows that exercise can induce angiogenesis in the capillary beds around skeletal muscles. An increased capillarization has been observed in training studies performed at 70–80% of VO2 Max whereas training at an intensity of 45% of VO2 max has been shown to have no effect on capillarization(1). This suggests that engaging in exercise at or just below threshold will promote angiogenesis. This is one of the many reasons we have our athletes utilize Sweet Spot focused training throughout the course of their season, but especially during their base phase.

Anaerobic threshold, FTP.

Improving Anaerobic Threshold 

Based on the information above it seems as though 2 main specific types of training will promote the adaptations needed in order to improve anaerobic threshold.

  1. Working CLOSE to threshold for extended periods of time, i.e. 2x20s.
  2. Performing HIIT WELL OVER threshold with brief rests, i.e. 30/30s, Tabata sets, etc.

Research has demonstrated that training at higher intensities is more effective than low-moderate training at improving mitochondrial function and the formation of new vessels through angiogenesis. Try to incorporate the following training methods into your program in order to improve your aerobic capacity and delay the onset of anaerobic threshold. 

Working CLOSE to Threshold

One method of improving your anaerobic threshold will come from training at or near your threshold. This level of intensity is also referred to as maximum lactate steady state (MLSS), and should be CLOSE to your FTP.
At this intensity, you’re putting a significant amount of stress on the system without going over the lactate tipping point. Depending on your training status, you can estimate the heart rate range, or power output, right around your threshold. Typically, this is equivalent to 70-80% of your VO2 Max.

REMEMBER, a 20 minute FTP test is an ESTIMATE of your anaerobic threshold, and you may need to modulate the % FTP you’re working at to ensure you’re working close your MLSS. In my opinion, most FTP tests OVER-estimate anaerobic threshold, and the Sweet Spot range (88-95% FTP) is actually closer to MLSS.

If you want a more accurate method of establishing your anaerobic threshold, I recommend utilizing software like INSCYD, or getting a true lactate threshold test at a lab.

HIIT

Interval workouts comprise of alternating short, high-intensity bouts followed by periods of active recovery. Typically, the high-intensity portion of the workout is performed at levels above lactate threshold. For well-trained individuals, this level will be close to their max effort. For untrained people, intervals should typically be performed between 120-150% of your FTP. This method of training is well documented to improve the lactate thresholds of both trained and untrained individuals.

A word of caution though, if you are relatively untrained, err on the side of caution with HIIT training as the power output required can lead to injuries and burnout if overdone.

However, if you are VERY well trained, taking a polarized approach can help you get to that ‘next level’. This typically entails an ’80/20′ approach where 80% of your training is performed at very low intensities (Zone 1/2) and the remaining 20% is performed at an all out intensity (Zone 6+). You also need to have a ton of training time available to squeeze the most out of this approach.

Conclusion

Hopefully this helps to shed some light on what is happening at a physiological level when you’re training, and what a good training program should be composed of that is focused at improving FTP. However, just like anything, every athlete is different and will respond better or worse to training stimuli. It’s up to the athlete, and coach, to utilize historical data and make educated decision on what works best for them. The more individualized you can make your training, the further you’ll progress in less time.

References

  1. Jensen, L et al. “Effect of high intensity training on capillarization and presence of angiogenic factors in human skeletal muscle” Journal of physiology vol. 557,Pt 2 (2004): 571-82.
  2. Lundby, C et al. “Adaptations of skeletal muscle mitochondria to exercise training” Journal of Experimental Physiology 101.1 (2016) pp 17–22

Triathlon: Swim, Bike, Run… and Eat?

As an endurance athlete myself, and working with triathletes, I always say that the fourth part of a triathlon is optimal nutrition. Without fueling your body with what it needs, your body may not perform as well as it could, and you run the risk of burning yourself out, both mentally and physically.

While many athletes are incredibly driven when it comes to their athletic training schedules, getting serious about the foods you put in your body is just as important.

In this article, we are going to talk about why fueling your body right is just as important as the training aspect of getting your body in peak shape for a triathlon.

Triathlon, Nutrition

The Importance of Nutrition for Endurance Athletes

When it comes to fueling your body for a triathlon, it’s important to keep a few things in mind. Nutrition for endurance athletes really encompasses what you will eat before, during, and after training. For triathletes, this is super important simply because of how rigorous training for a triathlon can be.

When you train for a triathlon, you are training for multiple different athletic events such as swimming, cycling, or running that will all occur during the triathlon. As you can imagine, your body is going to need some additional fuel to power through these athletic events. Not only will nourishing your body with the right foods help to support exercise endurance, but a healthy and balanced diet can help keep you healthy and reduce the risk of becoming depleted in certain nutrients.

Nutrition for athletes training for a triathlon is also very important for recovery. Since training can be hard on the muscles and joints, it’s important to fuel the body with clean protein sources to help nourish those tired muscles and promote optimal recovery. The body will also require adequate amounts of carbohydrates to help restore depleted glycogen stores.

Nutritional Guidelines for Triathletes

To help support energy reserves, it’s important for endurance athletes to get enough carbohydrates to support energy demands, protein to help repair worked muscles, and healthy fats to support energy and satiety. Adding a variety of fruits and vegetables to the diet can also help ensure that athletes are getting a wide variety of vitamins and minerals to help them stay in tip-top shape.

Here are some general macronutrient requirements to keep in mind when training for a triathlon.

Carbohydrates: Carbohydrates are essential for the endurance athlete, and they will serve as an immediate fuel source both during training and during the actual triathlon. It’s important to make sure that you are consuming enough complex carbohydrates as carbohydrate depletion can lead to things like fatigue, poor concentration, and poor athletic performance. It’s important to nourish your body with enough carbohydrates to help restore those glycogen stores that may have been depleted during athletic training. A good rule of thumb is to aim for 6-10 grams of carbs per kg of body weight per day. The actual amount you will want to get will depend on your physical fitness level and how long you train. Your body will require closer to the higher end of that range the longer you train and the more active you are each day.

Quality is also super important as you don’t want to consume just any type of carbohydrate. Strive to enjoy complex carbohydrates from things like fruits, veggies, and other fiber-rich options like rolled oats, quinoa, sweet potatoes, or brown rice.

Protein: Protein is going to play an essential role in supporting muscle recovery throughout training and even before, during, and after the triathlon. The general guideline for low to moderate endurance athletic training is about 1.0 grams of protein per kg of body weight per day. For very intense endurance training, that recommendation goes up to 1.6 grams of protein per kg of body weight per day.

Fats: It’s important to get enough healthy fat in the diet for a couple of reasons. For one, fats serve as another great energy source. Although the primary and immediate fuel source for athletes is carbohydrates, the carbohydrate stores in the body are limited to approximately 2,000 calories. During an intense athletic event like a triathlon, your body is going to need fat to help prevent the body from completely burning through and using up those carbohydrate stores. Since there are plenty of fat stores in the body, consuming enough healthy fats during training and as a regular part of a healthy diet can help ensure that your body is going to have the nutrient stores it needs throughout a triathlon. 

Triathlon, Nutrition

What About Nutrition DURING a Triathlon?

Since a triathlon involves three different endurance training events, it’s important to know that as you progress through each stage of the triathlon, your body requires different energy as well as nutritional needs.

One of the most important things to remember is to stay adequately hydrated and to replace those lost electrolytes you will be excreting through sweat. Staying hydrated can also help prevent cramps as you go through each event.

In addition to hydration, you also want to make sure that you are fueling your body with the right foods before the triathlon begins. You will want to enjoy your pre-event meal about 2-2.5 hours before the race starts, and aim for 1-2 grams of carbohydrates per kg of body weight. It is also recommended that you stick to foods you have enjoyed in the past to avoid introducing anything new that could potentially cause stomach upset. Stick to something fairly bland like oatmeal and fruit. NOTHING NEW ON RACE DAY!

During the triathlon, you will also need to continue to fuel your body to support energy demands. It is recommended that athletes consume 30 grams of carbohydrates per hour. Consuming healthy sources of carbohydrates throughout training is essential since carbohydrate stores in the body are limited. To make sure the body doesn’t run out, you can snack on things like sports granola bars or fruit. Just be sure to choose a food source that is free from any artificial ingredients and avoid anything with artificial sweeteners to avoid potential stomach distress.

After the triathlon is over, it’s time to support your body and replenish glycogen stores and nourish your tired muscles with the right foods. You will also want to rehydrate right away. Strive to consume a protein and carbohydrate-rich meal after the event with about 20-25 grams of protein.

The Best Foods to Fuel Your Body Right

So, we know that fueling your body right is an essential part of training and participating in a triathlon, but there is more to eating enough carbs, protein, and fat. Quality also matters, as quality is king when it comes to how well your body will perform.

Here are some great options when it comes to fueling your body with the right foods.

Healthy Carbohydrate Options

  • Rolled oats
  • Brown rice & brown rice pasta
  • Sports bars that are free from artificial ingredients
  • Fruits
  • Starchy vegetables like sweet potatoes

Healthy Protein Options

  • Grass-fed meat
  • Wild-caught fish
  • Eggs
  • Unsweetened Greek yogurt
  • Nuts & Seeds

Healthy Fat Options

  • Avocados
  • Coconut oil
  • Olive oil
  • Nuts & Seeds
Triathlon, Nutrition

The Takeaway

To help break this all down, here’s a reference on how you can fuel your body right when training for a triathlon.

  • Support your body with enough complex carbohydrates getting 6-10 grams of carbs per kg of body weight per day.
  • Aim to get 1-1.6 grams of protein per kg of body weight per day.
  • Consume enough healthy fats each day to help support energy levels and prevent burning through your carbohydrate stores too quickly.
  • Enjoy a carbohydrate-rich meal about 2-2.5 hours before the triathlon with 1-2 grams of carbs per kg of body weight.
  • Consume about 30 grams of carbohydrates per hour during the triathlon.
  • Enjoy 20-25 grams of protein with some complex carbohydrates after the event to help support muscle recovery and to replenish glycogen stores.

Optimal nutrition is such a key piece to athletic training. Getting the right balance of carbohydrates, protein, and fat is a critical part of making sure your body is nourished and can make a massive difference in how well you train. Strive to make nutrition a key part of your training plan, and use it as a tool to help you get the most out of your training, be at your best on race day, and recover more efficiently!


If you’re looking to learn more about sports nutrition, create flexible, sustainable, and indefinite habits when it comes to healthy food choices, and have a knowledgable Coach in your corner throughout the process, check out our Nutrition Coaching program.

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Resources

Sweet Spot vs. Zone 2 for ⬆️ Aerobic Capacity

Base training is a traditional phase of cycling periodization and is utilized by coaches and athletes alike to prepare their bodies for the greater physiological demands the build and peak phases bring, increase aerobic capacity while ideally maintaining anaerobic capacity, increase sport specific strength, and improve pedaling technique if needed; essentially you are training for the sake of training and improving, not for a specific race or goal. There has always been much debate over what ‘camp’ an athlete should choose – Traditional or Sweet Spot. This article will hopefully serve to make your choice a little easier, and if not, feel free to scathe me in the comments 😉


Why ‘Base’ Train?

Base training is all about bettering your aerobic capacity, improving your body’s ability to use fat versus carbohydrate to meet the energy demands of the muscle, and increase the percentage of VO2 Max at which you burn primarily fat (this can be lower than 50% for untrained athletes, and 90% for highly trained).

The key here is to stimulate and progressively overload your aerobic system WITHOUT having a huge accumulation of lactate (i.e. going above your ‘lactate threshold’). If you continually go above your lactate threshold and sustain it for a length of time, your body will prefer carbohydrate over fat to meet energy demands of the muscle due to carbohydrate being a more efficient supplier of energy (with caveats of course).

Quick Digression about Lactate

Before we move further, let’s speak a little bit in regards to lactate. Lactate is a product of glycolysis. Glycolysis is an energy system used by the body to break down glucose (stored as glycogen in the liver) into pyruvate and lactate. Think of pyruvate and lactate as teeny-tiny molecules that the mitochondria use to produce ATP (energy). The amount of pyruvate or lactate produced depends upon how much oxygen is present in the cells at the time of glycolysis.

In exercise where lots of oxygen is present (aerobic) your body will produce more pyruvate and less lactate. When you continue to push yourself into the higher power zones and above your lactate threshold, oxygen level in the cells will decrease and you will go into anaerobic energy production, thus producing increased lactate and decreased pyruvate.  Continue to push harder and the levels of lactate produced will continue to increase while pyruvate levels decrease. I.e. the fuel ‘mixture’ of fat (pyruvate) to carbohydrate (lactate) changes as an athlete works closer to their individual lactate threshold.

Back on Topic

Another issue in this argument is the amount of training stress (TSS) Zone 2 creates versus Sweet Spot…

Zone 2 for 1 hour

Sweet Spot, Zone 2
Image Credit – TrainingPeaks

1 hour at Zone 2 steady state (.65 IF) will provide approximately 42 TSS/hour.

Sweet Spot 2×20 Minute Intervals

Sweet Spot, Zone 2
Image Credit – TrainingPeaks

A 1 hour Sweet Spot focused workout (.9 IF intervals) produces 69 TSS, or roughly 30 TSS/hour more compared to Zone 2. Said another way, Sweet Spot training can produce roughly 40% more training stress per hour compared to Zone 2 with similar physiological changes and benefits! This is why GC Coaching uses it so frequently with our athletes that are on a time budget.

Planning your training off TSS is a great way to truly know if your training density is enough to create a positive return on your training time investment, and something I highly recommend you doing. Plus, it removes the guesswork from training and actually simplifies things once you understand it.

Now, let’s talk about the 2 methods of base training relevant to this article a little more…

What is the ‘Traditional’ way to Base Train?

Traditional base training involves doing A LOT of long duration riding at low to moderate intensity (i.e. Zone 2) with the goals of increasing capillary density, mitochondrial density, muscular endurance, and mental strength (pain tolerance). This sounds great in theory, but is it just an archaic way of thinking and training? Yes and no…Yes for the athlete who does not have 20+ hours per week to train and needs to get a better return on their training time, and no for the athlete who has oodles of time to dedicate to their training (remember training density). Don’t throw the baby out with the bath water though…

I utilize zone 2 training with my athletes when they are coming out of their race season and into their off-season to give them a mental break and remind them that they can just ride their bikes for enjoyment. Then again during their transition phase to prepare their bodies for the higher volume and intensities to come. Zone 2 is also where you spend a lot of time when you are cruising in the peloton during a race, so you need to be used to spending hours in this zone before race season starts. Most importantly though, Zone 2 is more than appropriate for the athlete who can spend enough time in it to achieve the required training density (TSS) for progress. This just happens to occur VERY rarely in my experience as most athletes work full time, have families, and other obligations aside from pedaling their bikes… Being an adult is hard sometimes.

So, if you don’t have hours and hours to train like a professional athlete, what should you do to increase your aerobic capacity? That, my friends, is where Sweet Spot training comes in.

What is the Sweet Spot Zone?

The Sweet Spot zone is between 84-95% (make it simple, and call it 90%) of your FTP, think high zone 3 and low zone 4…

Sweet Spot, Zone 2
Credit: Andy Coggan

This is called the Sweet Spot zone because it is smack dab in the middle of where you get the best bang for your buck in terms of return on training time invested. You can spend a lot of quality time here without building up undue fatigue which allows for greater repeatability and increased training density over the course of a training block.

Let me say that again and really drive that thought home… You can spend a lot of quality time here without building up undue fatigue which allows for greater repeatability and increased training density over the course of a training block. The absolute KEY with sweet spot training is the time you spend working in it, and the frequency at which you repeat it per week. Remember, training density, is what matters for fitness progress. If you can’t make more time in your schedule, the only other way to increase density is through intensity (i.e. Zone 2 versus Sweet Spot).

Most importantly though, you can spend a lot less time in Sweet Spot compared to zone 2 training and get similar physiological improvements. Thought of another way, espresso and coffee have a similar caffeine content, but you need a lot less espresso to achieve the same caffeine buzz.

Another Consideration

I’ve seen thousands of FTP tests and analyzed data from hundreds of athletes over the years, and it is my opinion that the non-lab FTP tests (those without a lactate analyzer) over-estimate FTP. I say this because the definition of FTP is:

The power output that a well trained, fresh, and motivated athlete can hold in a quasi steady state for 1 hour.

This is definitely possible with very highly trained athletes, BUT in my experience, most athlete’s time to exhaustion (TTE) is in the 30-45 minute range at FTP, NOT 1 hour. So, I would argue that the Sweet Spot range is actually closer, and more accurate, to an athlete’s true FTP (as defined above) and is a better approximation of lactate threshold which is what an FTP test is trying to estimate, in essence.

Benefits of Sweet Spot Training

Sweet Spot, Zone 2

The above table helps to really hammer the training density point home. As you can see, zone 2 training does help to improve a myriad of aerobic factors, but you need to spend ample amounts of time working in this zone to reap the benefits. Now, look at the Sweet Spot zone, you can achieve the same increases in aerobic factors, but in half the time needed compared to zone 2.

This does not mean to go absolutely bananas and do every single workout at Sweet Spot zone. Figure out, or ask a coach :-), what your races for the season will need to be done at in terms of length and intensity. Then, match the amount of Sweet Spot training to this with a goal of being able to maintain Sweet Spot for the longest climb in the race, your longest TT, or criterium/cross race length. For example, if you are a Cat 5 road racer, you don’t need to be spending 2 hours working at Sweet Spot when your longest race of the season will be 60 minutes.

“This all sounds awesome, Shayne!  You are telling me I can can workout for half the time and get the same benefits!?”

Not so fast my friends…

Drawbacks of Sweet Spot Training

Refer back up to the physiological adaptations table, notice that Sweet Spot training does jack squat for your anaerobic system, neuromuscular power, and fast twitch muscle fibers? This is a huge issue because athletes who specialize in road races, criteriums, cyclocross events, and track races rely heavily upon their anaerobic systems and fast twitch muscle fibers to generate breakaway power, power up a short and steep incline, accelerate after a sharp turn, and get off the blocks as quickly as possible. So, make sure you are using the later stages of your off-season effectively and not just increasing your aerobic capacity if you plan on competing in any of these events! There will be another article regarding the ‘Build’ phase of a periodized plan which will be more appropriate to speak about that.

Another drawback of Sweet Spot training is the ride lengths usually aren’t long enough for certain athletes. For example, an athlete who specializes in road racing will typically spend 3 hours+ riding their bike during a typical road race, but if they are only spending 90 minutes on their bike at a time, even if they are working at a respectable intensity, chances are they will not have the muscular endurance or, pain tolerance, to last for 3+ hours and be able to produce a decent enough kick at the end to win. So, make sure you are still getting out for those longer rides at least a couple times a month in the winter to maintain your muscular endurance and mental fortitude!

Wrap it up Already!

As the winter closes in and your training time invariably decreases, don’t waste your time spinning aimlessly at zone 2 if you can’t achieve enough training density doing so!  Instead, include some Sweet Spot work into your routine and continue to watch your FTP and fitness rise steadily throughout the winter.  Remember to not just spin at Sweet Spot though as you will indubitably lose your anaerobic and neuromuscular power. Finally, zone 2 still has it’s purpose! It is beneficial for those athletes who have a ton of training time available, are burnt out from a long season of racing, coming back after injury, or preparing their bodies for the high volumes and intensity of the build phase. Whatever camp you choose, just keep pedaling 🙂

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Blood Flow Restricted Training for Endurance Performance Gains

Blood Flow Restricted Training

There’s a type of training regimen out there that you may not have thought of using before. It’s called Blood Flow Restriction Training. I don’t know about you, but even the name kind of freaks me out a bit. I mean, cutting off my blood flow so that I can increase my performance? Are you crazy? But after delving into the research of it and having first-hand experience with it myself, it’s not as scary as it sounds, and it’s plenty effective.


How Does It Work?

Simply put, Blood Flow Restriction Training, or BFR for short, is a type of training in which you reduce the load and intensity of the exercise, while simultaneously restricting the blood flow to the working muscle.

But what does cutting off the blood flow actually do to the working muscle?

Well, there is still much debate on the topic, but many experts believe that cutting off the blood flow to the working muscle creates a metabolic overload that is usually seen in muscles that are performing higher intensity work, such as lifting very heavy weights or running at a very fast pace [1]. Not only this, but it also may be related to the decrease in myostatin that this type of training creates. Myostatin is a protein that actually inhibits the building of muscle and strength. Something that we do not want for sure. #gainsbro

What Does This Have To Do With Endurance Training?

Although much of the literature that exists on BFR revolves around resistance training, there is still plenty of evidence to show that it has benefits for endurance athletes as well.

One 2018 study illustrated that applying BFR to an 8 week cycling protocol was able to enhance quad strength and hypertrophy, as well as VO2 max more significantly compared to the group who performed the cycling protocol without the BFR [2]. What makes this very surprising is that this was achieved while producing less total volume than the non-BFR group. This could be a huge benefit from the time crunched athlete!

Implications for the Time Crunched Athlete

What we should also look into here is the greater opportunity for efficiency that BFR gives us as endurance athletes. If you’ve read my previous articles, you’ll know that it’s important to not only train for your particular activity but to also add in occasional strength training sessions throughout the week, as this is able to enhance your performance. However, the problem with this lies with the fact that it requires more total training time. This potentially takes away from other obligations you may have in your life, which can be quite inconvenient.

But with BFR, you’re able to simultaneously receive a strength training stimulus whilst also completing your regular endurance training activities. In the same study, an increase of 9% in strength was seen. While not as notable as a standard resistance training program would provide, it provides the endurance athlete with a “best of both worlds” scenario.

Interestingly enough, cross-sectional area was increased to the same level as resistance training would provide. Cross-sectional area is a measure used to quantify the size of the muscle and is most often utilized as a measure of hypertrophy. Though not the only factor associated with hypertrophy, evidence appears to be leading us to the fact that endurance training with BFR will be able to provide us with simultaneous strength and hypertrophy gains.

This isn’t just shown in a study in isolation either. What can be known as a benchmark in the BFR research world is a study by Ozaki and colleagues that showed us how 20 minutes of walking 4 days a week for 10 weeks was able to significantly increase the cross-sectional area of the thighs compared to walking without restriction [3].

Increased Variation & Possibilities

Probably the most remarkable aspect of BFR is the number of ways it allows you to vary up your training, while still providing you with the same amount, if not possibly more, of the training adaptations that you’re after.

Let’s look at injuries for example. When we’re pushing our bodies to the limit each and every day, they’re bound to happen at some point in our training career. With BFR, however, it allows us to train with much less load and intensity, which are two factors that would most certainly aggravate the injury further.

Another benefit that can be received from BFR during injury is the blood flow restriction aspect itself. One of the blood’s primary functions is to provide nutrients to organs and tissues throughout the body. What BFR does is keep the blood in the working muscle for longer periods of time. In essence, we are speeding up its recovery time as well, given that the working muscle is the one that is injured, or is associated with the injured tendon, ligament, or other neighboring tissue.

Another way to look at the possibilities with BFR is simply providing variation of to your training regime. The mind is probably our most important training tool. And if it begins to wander and won’t allow us to focus, then our training sessions are going to be half-assed and subpar at best. BFR provides a unique and non-traditional way to progress your training. Throwing this into your routine every so often and combining it with your standard training schedule will allow you to stave off boredom in your training. In this way, you’ll be able to stick to your training goals for the long haul… Remember, Fitness = Consistency over Time.

Simple BFR Protocol

  1. Choose a blood flow restriction device.

    This can be a compression band, wrap, or other tourniquet-like device.

  2. Wrap the material around your upper arm or upper thigh.

    DO NOT wrap your lower leg or lower arm. Doing so can result in nerve damage. ONLY wrap the UPPER portions!

  3. Choose your pressure.

    I suggest using a pressure of 4-5 / 10 for the upper body and 6-7 / 10 for the lower body.

  4. Do your workout.

    I’d suggest cutting the workload down by HALF. This can be accomplished by reducing reps, weight, or sets. Try it once a week to see how it affects your other training sessions.

BFR Example

Below is an example of an athlete utilizing BFR during a training ride. Notice he has the compressive force around the UPPER portion of his legs.

***You should consult your physician or other health care professional before starting this or any other fitness program to determine if it is right for your needs***

Conclusion

More and more research is being released each and every day regarding BFR, both in the realms of resistance training and endurance training. We’re really beginning to see how truly beneficial this type of training can be to stave off boredom, aid in rehabilitation from injuries, and even to help older individuals who may have limited functionality to train.


References

  1. Loenneke, J. P., Abe, T., Wilson, J. M., Ugrinowitsch, C., & Bemben, M. G. (2012). Blood Flow Restriction: How Does It Work? Frontiers in Physiology, 3. doi:10.3389/fphys.2012.00392
  2. Conceição, M. S., Junior, E. M., Telles, G. D., Libardi, C. A., Castro, A., Andrade, A. L., . . . Chacon-Mikahil, M. P. (2018). Augmented Anabolic Responses following 8-weeks Cycling with Blood Flow Restriction. Medicine & Science in Sports & Exercise, 1. doi:10.1249/mss.0000000000001755
  3. Ozaki H, Kakigi R, Kobayashi H, Loenneke JP, Abe T, Naito H. Effects of walking combined with restricted leg blood flow on mTOR and MAPK signalling in young men. Acta Physiol (Oxf). 2014;211(1):97–106.

Zwift: How to Fuel for a Long Ride

When it comes to long Zwift rides, and endurance training, one of the most commonly overlooked factors is recovery, and more specifically, nutrition.  Too much emphasis is placed on the physical work, and the amazing resource of proper nutrition and its ability to boost performance goes untapped.  Any athlete can slog through a long ride, but it takes true discipline to maximize performance a with pinpoint dietary intake.  Research has shown drastic performance differences between athletes that have the discipline to maintain a nutrient delivery protocol compared to those who don’t.  If taking your cycling to the next level is something that interests you, and/or you are getting ready to break your Zwift ride-time record, then keep reading below!


Intra-Ride Fueling

As you set out for a long Zwift training ride or race, you should be focused on ingesting foods and fluids that will support your glycogen stores.  Research has shown that for extended bouts of high intensity exercise, ingesting ~30–60 grams of carbohydrates per hour via a 12 fluid ounce 6-8% carbohydrate-electrolyte solution, every 10-15 minutes is the most effective means of supporting glycogen stores (3).  Simply stated, you need to ingest close to 15 grams of carbohydrates every 15 minutes—with a drink being the efficient method of delivery and easiest on the digestive system.

Not all sports drinks are created equal however.  Traditional ones are littered with unnecessary dyes, chemicals, and saturated with sugar, but it is super simple to make your own!  For a basic homemade drink, try mixing one to two tablespoons of honey, lemon juice (or any citrus), a pinch of sea salt, and a splash of coconut water into 10 ounces of water.  Get creative and make a drink that meets your digestive and taste preferences by adding in other ingredients.  The simpler the mixture, the less “extra” ingredients your body will have to digest.  Other great sources of sweetness for your homemade drink are maple syrup or pure organic fruit juice mixtures.  I personally prefer an apple/pear juice mixture with pomegranate, YUM!

Speaking of Hydration

Hydration is an often overlooked nutrient during endurance training, especially when riding indoors in a hot environment with limited air circulation and evaporative cooling.  Like glycogen stores, being hydrated is something that cannot occur from one day of increased intake.  It takes multiple days of strategic water intake to properly saturate the cells.  If ingested too quickly, the body will signal the need to expel water which will take vital minerals with it during the elimination process (1).  In the days leading up to your long Zwift ride or race, sip water continually throughout the day, accounting for 50-75% of your body weight in ounces at a minimum.  The amount of water needed is exceptionally higher if you train multiple times a day.

The effects of exercise induced dehydration on endurance performance are well documented with several studies showing that a 2% reduction of body weight can lead to higher levels of perceived exertion, increased core temperature, and increased cardiovascular strain (5).  To avoid the detrimental effects of dehydration, aim to match intake with water loss.  This may require more frequent drinking and should occur before the sensation of thirst arises.

Thirsty Yet?

If an athlete waits for the sensation of thirst to arise before drinking, then important physiological factors have already occurred.  Thirst is triggered by a monitoring system whose job is to maintain a homeostatic level of blood plasma.  There is an ideal value of hydration in blood plasma, and if this value dips below a specific level, the body releases hormones that will pull water from urine and the salivary glands in an effort to boost hydration of blood cells and introduces that terrible ‘dry mouth’ feeling.  These hormones, notably Antidiuretic hormone (ADH), will also shunt off blood flow from the extremities (i.e. legs!) and force it into the core (4).  This sequence of events can reduce your overall power output as blood is needed to provide oxygen and nutrients to those big ole quads.  Therefore, it is important that you are drinking continually throughout the ride and drinking before the sensation of thirst arises!

Avoid Palate Fatigue

Eating the same foods over and over can induce a reluctance to eat or even make some foods unpalatable.  Luckily, there is a huge variety of options out there if you are creative enough.  Dates are an excellent carbohydrate source and naturally have a mushy texture that allows for easy snacking.  They also act as an excellent “adhesive” for creating your ideal in race nutrition.  Try mashing up a handful of dates and rolling them out with a rolling pin, so that you have a date “sheet” or “foundation” about a half inch thick .  Add in some extra flavor layers that suits your digestive abilities.  A solid choice is a thin layer of nut butter, and a thinly sliced layer of a water packed fruit such as honeydew or pineapple.  Once you are satisfied with the contents, roll up the entire sheet and cut the sheet into bite sized chunks suitable for easy access and digestion.

Skip the Fats

Fats have a huge importance in an endurance athletes diet, but when it comes to long Zwift rides, it is best to skip fatty foods like nuts, seeds, oils, and large amounts of peanut butter and its variations.  Riding at high intensity and ingesting fats increases the potential for GI distress and a feeling of nausea. 

Optimize Your Protein Intake

Protein plays an important role in both pre-fuel and post-fuel nutrition for endurance athletes. Proteins play a massive role in the various functions of our body! It has been found that including some protein into your training may be able to help boost fitness performance. However, it is also important not to overdo your protein intake as this can lead to digestive distress. 

Here are some general protein guidelines to follow:

  • During Training: ½-¾ grams of protein/lb. of body weight per day during your training period. The Meal Before Your Event: Two to three hours before your event, strive to get 10-20 grams of high-quality protein in.
  • During Your Event: If you are exercising or training for longer than four hours, it is recommended that you get about five grams of protein per hour to help support performance and replenish your body. 
  • Recovery: Right after your event, you will want to replenish your body by getting about 10-20 grams of protein from a post-workout meal. 

Conclusion

Hopefully the information above has given you to the ammunition to build better dietary habits to boost performance over your next long Zwift ride.  Hydration, nutrient intake, and timing are essential if you wish to take your rides to the next level.  Remember, any athlete can slog through a workout, but it is the disciplined athlete that will maximize every detail to enhance performance!

The Training Book Ep.2: Shayne Gaffney / GC Coaching

“The Training Book” is a series which chronicles Bereda Training’s conversations with coaches, athletes, scientists, and industry thought-leaders as we seek to learn from the best and share knowledge with Endurance Athletes about how to improve, whether you’re a beginner, intermediate, or advanced. We discuss a variety of endurance sports, trying to gain insights from how different disciplines approach their craft. The idea is simple: if we talk to enough people, maybe we could write a book 😉

In this episode, Shayne Gaffney, Head Coach of GC Coaching, outlines the importance of helping athletes make important changes in their lifestyle in order to support their athletic pursuits.

He’s not just coaching Cyclists, he’s coaching people to become Athletes.

In the episode, he lays out his thoughts on the first few chapters of our eventual Training Book, which include:

  • Making Time
  • Building Habits
  • Athlete Mentality
  • Sleep
  • Nutrition
  • And generally… how to be an athlete.

Shayne has advanced training knowledge but works with a lot of beginner and intermediate level athletes and focuses on helping athletes set up their training and lives in unison in order to be successful on the bike. He takes a holistic approach to training.

Enjoy!

Hypertrophy: Gaming the System

Hypertrophy

You stretch after your workout in order to improve your recovery. You may even have dedicated stretching sessions throughout the day to improve range of motion and mobility. But did you know that stretching in between sets could be beneficial for your hypertrophy (muscle growth) as well?!

Wait a second. Why would you stretch in between your sets? What’s the purpose of doing that anyway? Well, in this article, I’ll tell you all about how recent scientific literature has examined this phenomenon and how you could possibly implement this strange but potentially effective method into your training routine.


What Exactly is Inter-Set Stretching?

This type of stretching refers to the utilization of various stretching methods (static, ballistic, dynamic, etc.) between sets of resistance training exercises, which would traditionally be used as a rest period. This is supposedly able to increase and optimize neuromuscular, metabolic, and hypertrophic adaptations [1].

Another added benefit of training with this technique is its efficiency. The time saved by omitting separate stretching routines may help increase adherence to training by limiting exercise time while enhancing both strength and flexibility adaptations, thereby, increasing efficiency [2]. Time-crunched athlete anyone?

Physiological Mechanisms

But HOW exactly does this work in terms of hypertrophy? Well, there are a few mechanisms that researchers believe are responsible for this.

Blood Flow Restriction

According to a study by Kirkebe and colleagues, changes in muscle length decrease both blood and oxygen supply to a stretched muscle [3]. Because of this, it utilizes the same mechanisms that cause growth in a well-known strength training regime known as BFR or Blood Flow Restriction training. This type of training has shown great promise in the scientific literature for increases in muscle strength and hypertrophy.

Although these mechanisms aren’t exactly clear, researchers hypothesize that it has mostly to do with the increase in what’s called metabolic stress. This is what happens when your body runs low on fuel stores during training and accumulates metabolites and waste products, usually during a given set. This often happens during high-repetition sets. The easiest way to practically think about this is the famous “pump.” This is a perfect example of this mechanism in action.

Signaling Pathways

Without getting too complicated into the physiological jargon, there are particular metabolic signaling pathways that tell the body to do certain things. One of these things is to control protein metabolism (protein synthesis and breakdown). One of the most well-known signaling pathways for protein synthesis (favors hypertrophy and tissue regeneration) is called mTOR. Some of the literature has shown that passively stretching the muscle (stretching with assistance, such as having a partner or using the wall to push you into a deeper stretch) leads to increased activation of the mTOR pathway [4].

Time Under Tension (TUT)

An often overlooked part of the equation to hypertrophy is the concept of time under tension. It’s exactly what it sounds like too. It’s simply how much time the target muscle spends under the load you’re putting against it. For example, when you’re performing a barbell bicep curl, there is a certain amount of time you’re performing the actual movement compared to the total duration of the movement. The time you spend bringing the bar up and bringing it back down count towards TUT, but the pause at the top and the time in between reps don’t.

A few studies have actually shown us that since static stretching increases time under tension, it plays a significant role for several muscular adaptations; primarily strength and hypertrophy. [5]. Static stretching is often the most well-known type of stretching. These include stretches such as the standing quad stretch and the cross-body shoulder stretch. These are performed using our own body, without assistance, and in a stationary position… Akin to our favorite ‘Nacho Libre’ stretch.

Decreases Acute Performance

Hold on. Didn’t you just say how it’s supposed to increase the level of my performance? Well, yes AND no. It most certainly isn’t a one-size-fits-all training regime. When we look in the short-term, it has been shown to decrease our performance in terms of how many total repetitions we are able to perform.

In one study, they focused primarily on how stretching between sets affected the number of repetitions the subjects could perform during high-rep exercise [6]. Subjects performed 3 sets of both triceps pushdowns and leg extensions at both 60% and 85% of their 1 rep max (1RM) across 3 different sessions. They also passively stretched the muscle for 30 seconds in between each set.

Unfortunately, they saw that the stretching group performed significantly fewer reps than the group who did not stretch at all. The researchers were not sure of the reasoning behind this, given the preceding success that was already current in the research. This could have to do with the particular sample that they chose and that some individuals respond to training much differently than others do. This could potentially be a positive for the time-crunched athlete however, especially considering you can achieve greater hypertrophy with less time.

Chronic Effects of Inter-Set Stretching

However, we see a completely different side of the spectrum here when we look at stretching and its effects on muscle over a longer period of time.

One study looked at the effects of inter-set stretching on flexibility, strength, and hormonal adaptations over a period of 8 weeks [1]. There was a control group (no stretching), static, and passive stretching group. Each group had a rest interval of 2 minutes between sets, with 30 seconds of it consisting of stretching.

What the researchers found out was that after 8 weeks of strength training, although there was no difference in hormonal adaptations, there were significantly greater gains in both strength and flexibility in both of the stretching groups, but not in the control group.

Practical Application

So, although this type of training is still relatively new in the world of strength training, I still would suggest implementing into your routine. It has its limitations but shows great promise in particular areas as well.

So what we discovered today was that inter-set stretching:

  • Acutely decreases high-repetition performance.
  • Increases flexibility over the long term.
  • Great potential for an increase in hypertrophy, but more research is needed.
  • Saves people a lot of time as it creates greater exercise efficiency.

So try throwing in 30 seconds of static or passive stretching in between your sets of strength training. It may or may not work for you. However, the only way to find out is for you to TRY IT. Until further research is released, trial-and-error is the only way to be sure if this type of training works for you or not. Let us know how it works out for you!

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References

  1. Souza, A. C., Bentes, C. M., Salles, B. F., Reis, V. M., Alves, J. V., Miranda, H., & Novaes, J. D. (2013). Influence of Inter-Set Stretching on Strength, Flexibility and Hormonal Adaptations. Journal of Human Kinetics, 36(1). doi:10.2478/hukin-2013-0013

  2. Simão, R., Lemos, A., Salles, B., Leite, T., Oliveira, É, Rhea, M., & Reis, V. M. (2011). The Influence of Strength, Flexibility, and Simultaneous Training on Flexibility and Strength Gains. Journal of Strength and Conditioning Research, 25(5), 1333-1338. doi:10.1519/jsc.0b013e3181da85bf

  3. Kirkebø, A., & Wisnes, A. (1982). Regional tissue fluid pressure in rat calf muscle during sustained contraction or stretch. Acta Physiologica Scandinavica, 114,(4), 551-556.

  4. Sakamoto, K., Aschenbach, W. G., Hirshman, M. F., & Goodyear, L. J. (2003). Akt signaling in skeletal muscle: regulation by exercise and passive stretch. American Journal of Physiology-Endocrinology and Metabolism, 285(5), E1081-E1088
  1. Mohamad, N. I., Nosaka, K., & Cronin, J. (2011). Maximizing Hypertrophy: Possible Contribution of Stretching in the Interset Rest Period. Strength and Conditioning Journal, 33(1), 81-87. doi:10.1519/ssc.0b013e3181fe7164

  2. Aydin, E. M., Ucan, Y., Yarar, H. (2017). The acute effect of static stretching between sets on the number of repetitions performance in resistance training. International Journal of Human Sciences, 14(4), 3913-3922.

Nutrient Timing: Paramount for Endurance Athletes

Nutrient Timing

Eating the right foods to support endurance training is just one piece to the puzzle. When you eat matters too. Nutrient timing is such an important part of endurance training and supporting your body with the right foods at the right time, but it is also a big topic of confusion as there never seems to be a clear-cut answer as to when exactly you should eat.  

In this article, I am going to clear up the confusion and dive into what nutrient timing is, why it’s so important, and what the science says about exactly when endurance athletes should eat.

Nutrient Timing

What is Nutrient Timing?

Nutrient timing sounds pretty simple, but it can be a bit complex. It’s about knowing when the best time to eat is before, during, and after training as well as what to eat. It is used to help support your body through endurance training for optimal athletic performance. But, nutrient timing is also focused on looking at how different foods impact your body at different times, which we will be covering next, so keep reading. 

Why Does Nutrient Timing Matter?

Nutrient timing can play a super important role in endurance training as you are literally fueling your body before training, replacing what has been lost through sweat, and providing additional fuel to keep blood sugar levels stabilized. Nutrient timing also involves eating to help replenish depleted glycogen stores and supporting muscle recovery.

Without eating the right foods at the right time, you run the risk of reduced stamina, low blood sugar, poor muscle recovery, and overall poor athletic performance.  

In addition to supporting the body for optimal athletic performance and recovery, here are some of the other benefits of nutrient timing. 

  • Improves overall health.
  • Supports nutrient positions-this is all about where the nutrients are going once you eat them.  
  • Supports better energy balance. 
Nutrient Timing

The Best Time for Endurance Athletes to Eat 

So, what does all of this mean for the kinds of food endurance athletes should be eating and when they should be eating them?

Let’s take a closer look at what and when endurance athletes should eat, based on the nutrient timing model.  

Fueling Before Training: 

When to Eat Before Training: It is so important to fuel your body before training, and it’s important to eat 30-60 minutes before training begins. 

What to Eat Before Training: So, what should you be eating before training? It is best to enjoy a carbohydrate-rich snack that is around 200-300 calories. You will want to stick to carbohydrate-rich foods and try to avoid anything that is too high in fiber or too high in dietary fat as they can be harder on the digestive system. Some great choices include sweet potatoes, oatmeal, bananas, brown rice pasta, unsweetened Greek yogurt with granola and raw honey. You want to provide your body with an easier source of fuel that will be used directly for energy support during training. 

It is also important to hydrate your body. Ideally, you will want to start hydrating 2-4 hours before you start your training and then continue to drink water throughout exercise, ideally containing some Skratch powder.  

Fueling During Training:

When to Eat During Training: When it comes to endurance training, you will need to replenish your body with a fuel source along with staying hydrated. Studies have shown that athletes need to consume carbohydrates throughout training if they are active for longer than 1-2 hours. The studies have shown that adequate carbohydrate intake for endurance athletes training for 1-2 hours would be 30 grams of carbs per hour, 60 grams of carbs per hour for training 2-3 hours, and 90 grams of carbs per hour if you are training longer than 2.5 hours. As you can see, the longer you train, the more carbohydrates you will need. Be warned though, once you start approaching 90 grams per hour, you have a higher risk of digestive problems. So, practice before the event / race to see what your individual tolerance to carbohydrate absorption is. Some of my athletes can consume 110+ grams per hour with no problem, where others are lucky to ingest 60 grams.

Studies have also found that high-quality carbohydrates boost physical performance. High-quality carbs are what fuels and sustains an endurance athletes energy levels. High-quality carbs have been found to provide muscles with energy needed for endurance training. 

Protein also plays an important role during training as it can help prevent muscle breakdown. To help support the body’s protein requirements, strive to get 20 grams of protein in during long periods (over 2 hours) of training, but don’t consume all 20 grams at once. Try to stay below five grams of protein per hour of training to help reduce the chance of digestive upset. 

What to Eat During Training: To help support your muscles and energy levels during training, you can snack on things like grass-fed jerky for protein, and whole-foods bars made with fruits and whole grains for carbs. Bananas and other low-fiber fruits like melons can also make a good carbohydrate fuel source.

Nutrient Timing

Refueling After Training: 

When to Eat After Training: After training is when your body really needs to refuel and replenish those depleted glycogen stores. Eating after intense exercise is also essential for proper muscle as well as tissue recovery. To help support muscle recovery through muscle protein synthesis and to replenish glycogen stores, it is important to eat a protein-rich meal with some complex carbohydrates as soon as you are finished training. Ideally, your meal should contain 20-25 grams of protein after endurance training. 

A meal rich in carbohydrates that is easily absorbed and digested right after intense exercise can also help support what’s called glycogen resynthesis which involves glycogen replenishment post endurance training. Studies have found that endurance athletes can achieve total muscle glycogen resynthesis within 24 hours when consuming an average of 500-700 grams of carbohydrates over that time frame. 

Since glycogen resynthesis tends to be at its peak within the first two hours after training, you can boost glycogen resynthesis by consuming 0.70g glucose/kg body weight every two hours. 

What to Eat After Training: A great way to get both protein and carbs is to make a nutrient-dense post workout shake which contains:

  • Unsweetened almond milk.
  • Unsweetened raw cacao powder.
  • Some full-fat unsweetened Greek yogurt.
  • A frozen banana.
  • You can add a tablespoon of pure maple syrup and some added superfoods like chia or flaxseeds as well.

Drinking this immediately after training will help support both muscle recovery and provide your body with the carbohydrates it needs to support those depleted glycogen stores. It also makes a really easy and convenient way of getting your carbohydrates and protein in without having to make a meal immediately after training.  

You will also want to enjoy a balanced meal about two hours after training to continue to help replenish and nourish your body. 

Nutrient Timing

The Importance of Fueling Throughout the Day & On Non-Training Days 

Nourishing your body with optimal nutrition on non-training days is just as important as it will help to support your muscle recovery and nourish your body with what it needs to be in tip-top shape. 

Be sure to consume at least three balanced meals each day with two nutrient-dense snacks in between. Meals should have a balance of complex carbs, clean protein, and healthy fats. Snacks can include things like two hard-boiled eggs with a side of fruit, or a half of an avocado sprinkled with sea salt. 

The Takeaway 

To help sum this all up, here’s a breakdown of what you need to know. 

  • Eat 30-60 minutes before training fueling up with a carbohydrate-rich snack between 200-300 calories. 
  • If training for 1-2 hours, consume 30 grams of carbs per hour of training, 60 grams of carbs per hour for training 2-3 hours, and 90 grams of carbs per hour if training for more than 2.5 hours. 
  • Strive to get 20 grams of protein in during long periods of training, getting five grams of protein per hour of training to avoid digestive upset. 
  • Post training, try to eat right away and consume 20-25 grams of protein and 0.07g of glucose/kg of bodyweight every two hours. 

Nutrition plays such a critical role in how well your body performs when it comes to endurance training, and nutrient timing can be such a useful tool in helping your body function at its best. Try implementing these tips and time your meals and snacks appropriately to get the most out of your training. Many athletes are surprised at how much better they feel before, during, and after training with just a few adjustments to when and what they eat. 

If you’re looking to learn more about sports nutrition, create flexible, sustainable, and indefinite habits when it comes to healthy food choices, and have a knowledgable Coach in your corner throughout the process, check out our Nutrition Coaching program.


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Resources 

  1. Ryan Andrews. Precision Nutrition. All About Nutrient Timing. 
  1. Friedman JE, Neufer PD, Dohm GL. Regulation of Glycogen Resynthesis Following Exercise. Dietary Considerations. https://www.ncbi.nlm.nih.gov/pubmed/1901662 
  1. Asker Jeukendrup. A Step Towards Personalized Sports Nutrition: Carbohydrate Intake During Exercise. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4008807/ 
  1. Kimberly Mueller, MS, RD, CSSD. The Triathlete’s Guide to Protein. http://www.ironman.com/triathlon/news/articles/2016/01/triathletes-guide-to-protein.aspx#axzz5dd91yc5x 
  1. An Athlete’s Guide to Everyday Nutrient Timing. https://www.hprc-online.org/articles/an-athlete-s-guide-to-everyday-nutrient-timing