Nutrition, Podcast, Training

Workout fueling – best practices of top coaches | EP#306

 October 4, 2021

By  Bernardo Gonçalves


Workout Fueling - That Triathlon Show

In this episode, coaches Frank Jakobsen, Val Burke, Kolie Moore, Ryan Bolton and Björn Kafka each give their perspective and recommendations on how to fuel workouts. 

In this Episode you'll learn about:

  • How much energy to consume for different kinds of workouts? 
  • In what form should you consume energy?
  • Pre- and post-workout fuelling
  • Is there a time and place for "training low" - i.e. training in a state of low glycogen (e.g. fasted training)
Quick Navigation

Sponsored by:

Precision Fuel & Hydration
Precision Fuel & Hydration help athletes personalise their hydration and fueling strategies for training and racing. Use the free Fuel & Hydration Planner to get personalised plan for your carbohydrate, sodium and fluid intake in your next event. That Triathlon Show listeners get 15% off their first order of fuel and electrolyte products. Simply use this link and the discount will be auto-applied at the checkout.

Zen8 Swim Trainer Logo

The ZEN8 Indoor Swim Trainer allows you to improve technique, power, and swim training consistency. You can target specific aspects of your stroke, like catch and pull-through, work on core activation and body position, and make sure you stay consistent in your swim training even when you don't have time to go to the pool. Try the Zen8 risk-free for 30 days, and get 20% off your first order on


Frank Jakobsen: general thoughts on workout fueling

04:52 - 

  • First, reflect on what your strengths and weaknesses are in the sport compared to your goals.
  • Then decide if you want to develop these strengths and weaknesses based on a good evaluation. Thus, you can make a better decision.
  • After, think of what you want to develop for the coming season. And understand how you are going to do that. You might want to work on run speed or endurance on the bike or strength within others.
  • Only after those steps, you can start looking into the nutrition side. Understand the strategies that will help you develop and progress over time.
  • If your swim and bike are good, but the running is a problem, maybe one strategy would be to lose a bit of weight if the athlete carries a lot of fat. So, we identified what we should do.
  • This weight loss would benefit the running performance. Once we understand the specific weakness, the focus should be on how you will lose weight.
  •  And, of course, nutrition plays a role in weight loss. So, you would need to adjust your diet over 3 to 6 months to lose those 3 to 5 kg of fat.
  • On the other hand, if the athlete is too skinny, the swim and bike might be a problem. The athlete does not have body fat and "sinks" in the water. He might not be strong enough to ride 180 km on the bike because of a lack of endurance.
  • Maybe, the athlete forgets to eat on long endurance rides and suffers in them. And that could be a reason for being too skinny.
  • And also, he might get injured too often because his body does not hold the stress of running.
  • With this information, the athlete wants to get more robust and resilient. And he wants to do an Ironman.
  • What the athlete goal is to put some muscle, so he defined the problem. And then, you adjust your training and nutrition to help you achieve that goal.
  • Without addressing the nutrition, the athlete will not get the results he wants.
  • For both athletes, the training and nutrition strategies would be different. The athlete that wants to lose weight will not do it two months or six weeks before the race.
  • I see a lot of people not thinking of periodisation and wanting to lose weight all year round.
  • The problem is that those two months before the race are the ones with the higher training loads. Therefore, the ones where you will get the condition to perform at your best level.
  • If you have not lost weight until this period, this is not the time to do it. You might lose half or a kilo of weight. But if you are losing more than that, you will not be able to sustain the training. And also, you will risk getting sick or injured.
  • Therefore, the periodisation needs to account for that period of fat loss. The training in that period will also be different.
  • In conclusion, the training and nutrition are the same in the weeks before a race for both athletes. But in the winter phase, they might eat differently.
  • "Training hard and losing a ton of weight" - forget the last part because that is not possible at the same time. When in training camps, I see a lot of people under fueling during training. And at dinner, they eat everything they can because they trained for 6 hours and are hungry.
  • The next day they try to eat even less during the workout. The thought is that they ate a lot at dinner the night before. Therefore, they should eat less in training. Eating less becomes counter-productive for training stimulus. The glycogen stores will get lower and lower, meaning you can only hold a certain pace because you rely only on the fat stores. Therefore, you will not produce as much work as you can. And you will not stress your muscle as much.
  • That is why it is fundamental to understand what we are trying to achieve. If we want to build endurance, we should focus on fueling the proper food quantity in training to train for longer.

Frank Jakobsen: nutrition strategies leading up to an event

13:50 -

  • The nutrition in training will depend on the purpose of each session. If the goal is to perform (weight and training status are ok), the attention on fueling is fundamental. Ironman athletes, without a proper nutrition plan, will struggle because of glycogen depletion. They burn so many carbohydrates during the swim and the bike that they burn out all the glycogen from the muscle fibres. That is the glycogen most accessible to enter the mitochondria and produce energy.
  • We also want to be efficient and choose our pacing strategy wisely. The goal is also to use fat as fuel. Fat is burnt at a slower rate because it takes a lot more time to enter the cells.
  • In an Ironman, the intensity is not that high. Therefore, fat is a good fuel and a good energy source.
  • For example, if you choose your bike pace where 80% of the energy comes from sugar. And if you can improve your efficiency at that pace (meaning lowering the sugar consumption to 70 or 60%), you have to digest fewer carbohydrates during the race. (something that can avoid stomach problems)
  • And you will also use fewer carbohydrates from your liver. This means you get further on the run before you get in trouble. The goal is to get to the finish line without burning all the carbohydrates available in your body, the fastest energy source for moving.
  • In conclusion, in training, we try to become more efficient in using fat and stressing the body just enough to be more fit and strong.

Frank Jakobsen: example of application of a nutrition plan

16:40 -

  • First, we take the athlete to the lab, and we evaluate the metabolic efficiency. At 220 W, 80% of the energy source is carbohydrates, which is high.
  •  If the athlete wants to do 220 W for the full Ironman bike split, he might adjust the goal and lower it to 200 W. 
  • We measure the athlete again. At 200 W, 70% of the energy source is carbohydrates. However, to be competitive, the athlete wants to do 220 W.
  • The athlete is strong enough to push 220 W, but he will run out of glycogen for the run.
  • Therefore, we tell the athlete to eat 60 to 120g/h of carbohydrates in the longest session of the week. The amount depends on the size of the person and how much he is burning.
  • And in 1 or 2 days of the week, we might say to ride three hours at race pace without energy input. It forces the body to take in fat as an energy source in the last hour of training.
  • That is training the body and the metabolism to get more efficient at that certain intensity.
  • Then you can tell the athlete to go in the fat max area and do a fasted session at that intensity. Fasted sessions will help you get more efficient at using fat. 
  • If you do it for a month, the sugar burn rate at 220 W might reduce from 80 to 70%.
  • This carbohydrate restriction training I would be careful when applying to women. If it is a man and efficiency is not good, we could force it a bit more during a period. But this will depend on the period of the season.
  • For women, I do not even do it. For some people, we might even restrict carbohydrates at the beginning of a long session. And eat after a certain period. In that way, at the end of the session, you can still push on the pedals and maintain the power and speed.
  • We also have to look at injury history. When you do it, you are burning fat. And when you burn fat, you need to consume more oxygen (three times more than when burning sugar). This causes oxidative stress in the body. Oxidative stress is the result of the appearance of free radicals. Its accumulation over time leads to inflammation, irritation and injuries.
  • Some people even try to get into a ketogenic state. In this state, the body starts to alter what it is using for fuel.
  • My experience with this is an absolute disaster. The general rule is that you have to consume less than 50g of carbs per day. In this way, you are altering the body's metabolism.
  • That means you will be able to use 60 to 70% of the energy from fat at race-pace in theory.
  • I have seen the numbers, and for me, they do not add up.
  • It puts a lot of stress on the body. And if you do it for a long time, people lose absolute power.
  • You would be efficient at race-pace, but not ideal to have training stimulus.
  • If you do too much and try to force fat burning for too long, it will hinder our performance ultimately.

Frank Jakobsen: fueling for athletes with more training volume

24:23 -

  • If the athlete is in blocks with more training volume, we will be fueling a lot in every session. We do it because of how metabolism works.
  • If the athlete is stressing the body with 30 hours of training, your metabolism is high to repair the body. It is not like, on some days, your metabolism is slower. And on higher intensity days, the metabolism is faster.
  • We notice the metabolism is higher especially, after days you do not eat enough. You empty yourself. And this lowers your immune system, and it will decrease performance in the next few days.
  • When training for an Ironman at race pace, you are already burning a lot of fat (working on that zone 2). So making sure you are well-fueled to get the benefits and fitness gains of that volume of training.
  • To be well-fueled, you do not need to eat only gels. You mix it up with honey, gummies, homemade rice cakes.
  • The more carbs you can get, the better. It is crucial to maintain training consistency. And recover after.

Frank Jakobsen: pre- and post-workout fueling recommendations

27:31 -

  • Pre-workout fueling is just eating. Eating breakfast and go.
  • If you have a technical or zone 2 swim session for up to an hour, you should be able to do it without breakfast.
  • If you have a high-intensity session (e.g. 10x400 meters with intensity progression from zone 1 to 3), you get to halfway, and it starts to be hard to keep the intensity. It is ok if you cannot hold the pace because of a lack of endurance and strength. In these situations, you taper it down and work progressively over time.
  • If that is is not the case, we evaluate the athlete's last days. And most important, we check if they have eaten before or during the session.
  • The athlete might not want to fuel during a swim session because we are at a horizontal position.
  • However, if they are burning mainly carbs (high-intensity efforts), they will not sustain the intensity.
  • The muscles are ready for the stress, but they are not getting enough fuel.
  • Therefore, they are not taking out the effects of the hard swim sessions because of being in a low energy state. To get the most of hard swim sessions, bring energy to the swimming pool.
  • The same on the bike. If you have 5x8 minutes at the threshold and halfway through, you start to feel empty, lower the intensity. The definition of threshold is the point where 100% of your energy comes from sugar.
  • One solution for this problem is to wake up a bit earlier to have a proper meal before heading into the swimming pool. If you decide to go to the swimming pool in a hurry, do not take an energy bar twenty minutes before going there.
  • Enter the swimming pool, start swimming and then fuel while training to sustain the intensity.
  • In cycling, there are examples of athletes coming out saying they wasted years of their careers because of a lack of fueling. (Jakob Fuglsang mentioned that he lost 8 years of his career eating too little)
  • If you are running low on fuel, you will not complete the session. And you will miss the training stimulus of your muscular, breathing and cardiovascular systems.
  • My message is not saying: "Let's use sugar all the time".
  • My message is that in some periods of the year, the goal is not losing weight. In other periods of the year, for some people, the focus is optimizing their fat-burning ability. And even lose some body fat like that. But you have to be careful what times of the year you are trying to do it.
  • And it all comes down to start by defining the goal. Know the weakness I want to work on and how I want to develop it. And how my nutrition is going to aid in that development.

Val Burke: general thoughts on how to fuel workouts

37:50 -

  • My nutrition thoughts will depend on the training duration and intensity. 
  • It depends on the athlete experience (beginner vs advanced athlete with many years of training). Beginners are often not as efficient and get a lot hungrier. 
  • And concerning racing, we also need to train the gut and, of course, that will also change my recommendations.
  • Starting with training duration, if you are training above 75 minutes, I recommend having some fuel. You can have some carbs, but the intensity will give you some flexibility.
  • If the intensity is low, you can have a mix of nutrients. Have primarily carbohydrates, but also fat and protein. This fact gives you a wide range of products in the market you can get. 
  • A lot of my athletes enjoy a lot of whole foods as well. And over the years, they made their recipes and used them in training. And then, they reverted to sports products to mimic their race in race-specific training.
  • A lot of the commercial products are good. My favourites are energy balls (mixing dates, fruit, almond milk, a little bit of coconut oil), bananas. And a lot of my ultra-endurance athletes on their low-intensity rides might have roasted vegetables (boiled potatoes with a bit of salt).

Val Burke: differences in nutrition recommendations for beginner and advanced athletes

42:11 -

  • Based on the feedback I got, new athletes find that they are hungry all the time. When their energy levels get low, they tend to "bonk" a bit faster than advanced athletes.
  • I am sure that their pacing strategy explains this difference. How hard the beginners perceive a certain intensity. But I do believe that this all comes down to efficiency.
  • The athletes with more years of endurance training can get by with less food on the low-intensity sessions.

Val Burke: how much to consume for different sessions

43:22 -

  • If we start with the lower end, I could start with 0.5 grams per kilo of body weight. So, for a 70 kg athlete, that would be around 35 grams per hour. This amount is for someone who wants to be on the lower side on lower-intensity rides.
  • However, sixty grams is often a usual recommendation (if the session is a bit more intense and they want to keep that intensity during the whole session).
  • For the lower end, it is where you can mix the nutrients. But if you want to sustain a higher pace for longer, you probably find that digestion would start to be a problem.
  • For high-intensity workouts, we can look at sixty grams as being the lower end. And with race-specific training, you want to mimic the racing nutrition strategy. Athletes might perform these sessions a couple of times per month, leading to a race.
  • In the race-specific sessions, they would start at sixty grams and would increase the amount over time. (If the digestive system allows them to)
  • If you are well-fueled and perform Vo2 max or threshold efforts, you can empty your glycogen stores in twenty minutes.
  • For short, high-intensity workouts of less than 1 hour, you could fuel throughout the hour. For example, if you are doing 3x7 minutes at the threshold, you might get away eating or like 30 to 45 grams of carbohydrates. And you could start eating 30 minutes into the session. But of course, this depends if we are talking of intense training one hour in duration or one hour, including the warm-up.
  • But this depends on the amount of intensity the athlete does. And sometimes, I prescribe race nutrition for those so that the athletes can also train the gut and see if their digestive system allows it. 

Val Burke: situations where you could try to go without fueling

47:37 -

  • The fasted training and training low (meaning with no carbohydrate intake) have been trends in the last years.
  • I have used it with athletes, and I have had athletes that tried to go for three hours without eating. But I see many overall problems with that. Therefore, I am not a fan of it.
  • The theory is that most triathletes are in a fasted state in some way because they train two or three times per day. An age grouper even has to work in between the sessions.
  • I only prescribe it if the athletes want to try it. And if they try it, it might be two days per week. For example, in one of their early morning sessions, they do it in a fasted state. And those sessions would be a maximum of one and a half hours to two hours of training. Of course, they would be low-intensity sessions.
  • What is interesting is that most of the athletes that tried it go back to good fueling. The reason is they found out it works better for them.

Val Burke: nutrition recommendations for athletes with high training volume

49:55 -

  • When I start training with an athlete, I ask them to fill in a training log. And I have a slot every three hours. With this, I would like to see something every three hours. You could decide to eat six small meals. We do not enjoy seeing gaps of long periods without eating. And that is for everyone. (Professional athlete or amateur)
  • Simply what happens is that your body can get into an energy deficient state, which is one season that might be ok. But I have seen athletes run into problems long term, the reason being in that energy-deficient state.
  • Having a late-night snack can help you. (especially if you are doing an early morning workout and training twice per day)T
  • This snack should include some carbs, but protein is the nutrient to look at before sleeping. We get the best protein syntheses when we are sleeping.
  • And then the other crucial time is the thirty minutes after training. That seems to affect a lot of health indices. If you miss that thirty-minute window, often you find you feel lethargic the next day. And your glycogen stores have not had that instant refuelling.
  • But there is also blood variables and hormonal effects that are affected by that thirty-minute window. Therefore, if there is something you need to pay attention to is that post-workout meal in that time gap.
  • There are many commercial products with good research to back them up. But there are also whole foods that you can eat.
  • Therefore, smoothies have been around for a while. And milk is good for providing protein (2 types of protein) and some carbohydrates. Thus, adding milk to your smoothies or fruits is beneficial. (Berries because of their antioxidant properties and bananas because of their carbohydrate content) 
  • You can also put Greek yoghurt, Oats, nuts and seeds (you are getting some fats and protein).
  • One other thing that you can do is a mug cake. It has bananas, peanut butter, cocoa and milk. 
  • For my daughter, that is her post-workout recovery snack. No flour, but it gives protein and carbs as well.

Val Burke: late-night protein snacks

53:56 -

  • For a late-night snack, again, there is a lot of commercial products you can get.
  • But greek yoghurt seems to work quite well. A glass of milk as well. Milk has whey and casein in it. 
  • Maybe also a smoothie. Not too much, but for endurance athletes, we have been carb focused for many years. And we have a lot of tissue turnover.
  • If you look at tendons, muscles, and the damage you are doing in some sessions. It is fundamental to get the protein needed to repair that. And that late-night snack seems to be very effective.

Val Burke's final take-home lessons

55:01 -

  • I think when you go, specifically to long-distance triathlon, nutrition will make or break you. 
  • So, we focus a lot on training. But I believe the more we take care and have good nutrition, the better you will sustain your training workouts. And the better your health will be in the long term.
  • Therefore, do pay attention to it. I have had many athletes that even adding the thirty-minute post-workout recovery snack has made a difference in their health and hormonal levels. And also on how they feel.
  • And that is something you can plug into your training. It means plug thirty minutes after the workout to make yourself a good snack and recover.

Kolie Moore: general nutrition recommendations

57:56 -

  • I think it is pretty similar to what others might recommend. If you have a longer or a tough session, you need to eat more. 
  • If you are going easy and for one hour only, you need to eat less, or even you do not need to eat. (for a one-hour recovery session, you do not need one hundred grams to fuel that)
  • If you perform high-intensity efforts, you will burn a lot of glycogen and glucose. Therefore, you need to fuel that appropriately.
  • Concerning the duration aspect, I am fascinated by ultra-endurance athletes. If you are in a race for twelve or twenty-four hours, the intensity is mainly low. But you are also spending energy and without being able to have proper meals.
  • Therefore, the nutritional aspect is more than "we need to eat more carbohydrates". It is more: "How do you nurture the needs for your body on the bike or while running in these super-long events?"
  • That is something that my team is always looking at in ultra-endurance events.
  • Nutrition will make or break an ultra-endurance athlete's performance.
  • Even in an eight-hour training ride (which is super-long), many athletes will skip protein and fats on those rides. And I think that is a mistake. It is better to stop for twenty or thirty minutes and have a proper lunch or a sandwich.
  • For a short, high-intensity workout, if you consume a proper amount of carbohydrates, you will perform well in the session. For one or one and a half-hour high-intensity training rides, some people cannot eat. Their gut will not accept the food.
  • Drinking an electrolyte drink with some sugar in it or even Scratch Superfuel could be beneficial.
  • I would say that fueling beforehand, with many carbohydrates (two/three hours before the workout), can be good.
  • But if you stretch to the two or three-hour duration, you will have some rest in there. You will need to eat in that kind of workout. I would recommend (depend on the power you are putting out) at least fifty or sixty grams of carbs per hour.
  • And if your FTP is high, you will produce a lot of kilojoules, and you will want to eat more than that.

Kolie Moore: relation between the duration of the workout and the fueling requirement


  • I believe that duration has an impact on what and how much you should eat.
  • For a typical two to five hours session, I would recommend something like forty to fifty grams of carbs per hour (if your FTP is within the 200 to the 300-watt range).
  • But once you get to an FTP in the mid 300s to low 400s, people feel the need to eat seventy to ninety grams per hour. (even in endurance sessions)
  • I worked with a couple of athletes with a high FTP. But they do not have much base training. Therefore, their endurance is not that good. So, they need to eat these low-intensity sessions with one hundred grams of carbs per hour. They need this to be ready for the next day.
  • Fueling for the workout you are executing is part of the recovery process for the next session.
  • Your body is a good energy accountant. When you spend many kilojoules on a training day (e.g. averaging 250-300 W), you will feel hungry at some point. And eating during that session is pre-fueling for the next workout, whether it is later in the day or the next day.
  • A lot of the aerobic adaptations we make occur regardless of how we eat. Just because you are eating carbs during a long-endurance session does not mean you are going to negate any adaptations.
  • If you can put more power and last a little longer by eating, you will get more adaptations.
  • And regarding the type of fueling and Fasted rides or low-carbohydrates sessions, I never advocate fasted sessions personally (unless it is an hour recovery workout). Any longer or harder than that and I think it is essential to fuel properly.
  • Otherwise, you will put yourself in a hole. And I have seen many athletes doing this and burning out because of it. Especially if they are trying to lose too much weight too fast.

Kolie Moore: the case for fasted or glycogen-depleted workouts

1:05:59 - 

  • When people think about concepts like Fatmax (the intensity where you burn more fat), there seems to be a belief that just because you are burning more fat does not mean you get better at burning fat.
  • FTP extensive work is also another type of endurance training that will help you burn more fat. It also will make you lose more glycogen.
  • People should think of the reasons that keep us from burning fat. And why we want to burn more fat.
  • We want to burn more fat because it spares glycogen. But what limits the amount of fat we can burn is transport from fat tissues. And obviously, there are intra-triglycerides we can burn.
  • When we want to improve that, all kinds of workouts (high volume or extensive FTP work or any type of extensive work) will benefit fat burning.
  • When I prescribe athletes low-carbohydrate workouts, it works like this: fuel, as regular, the session of the day before. Afterwards, you can get a good amount of carbohydrates. But for the rest of the day, decrease the carbohydrate content. 
  • However, make sure you are not in a caloric deficit. Your adipose tissue is an endocrine organ in a way. And will send signals like: "We are empty. You better eat." It could give problems later, typically seen in endurance athletes in an energy deficient status. They have Poor training and accumulation of fatigue within others.
  • I would prescribe this once or twice per week. One of the things we are doing is we are teaching the body to transport fatty acids better. And especially across membranes.
  • A critical component of the transport of fat into the mitochondria is the CPT1 and CPT2 and the carnitine shuttle.
  • By doing these sessions for a month or two, the amount of time we can hold the FTP goes out. That indicates fat reliance. I think it is better of an increase in carnitine stores and improvements in the whole chain.
  • On my podcast, the latest series I have been doing is about metabolism. We dive into how we break down glucose, fatty acids. What limits the fat acid transport. And in future episodes, we will talk about if you should do keto diets (no). We will talk about VLaMax and that sort of stuff.

Kolie Moore: types of athletes that could benefit from these sessions

1:11:29 -

  • These implementations are not as usual as they used to be. One thing that I found is that fueling a low-carbohydrate workout is tough while maintaining an isocaloric diet.
  • Some people will under-fuel. Others do not like it. 
  • But for those that like it and it works, we will do it for a month or two. And we do it with most endurance athletes.
  • It is pretty much anyone who wants to increase FTP and increase TTE (time to exhaustion). And then, we do Vo2 Max work and a bump in the FTP because of that.

Kolie Moore: thoughts on what to eat during sessions

1:12:59 - 

  • In general, whatever someone likes to eat is what they should eat. And once the food consumption or type of food becomes an issue, we will get something else.
  • It is individual to each athlete. Some might like to eat one thing, and others might not. Whatever you have is fine until it becomes an issue.
  • For glycogen depleted sessions, I recommend people to eat carbohydrates during those workouts. One of the things that happen is that you are still using carbohydrates to do the sessions. 
  • Therefore, when you start glycogen depleted stores, you are close to "bonking" for the whole ride. By consuming carbs during these sessions does not mean you will get fewer adaptations.

Kolie Moore: post-workout nutrition tips

1:14:29 -

  • High-intensity sessions use a lot more glycogen than most people think. In these sessions (e.g. thirty second all-out sprints), the work in kilojoule spent is not that high.
  • The difference between aerobic oxidised carbohydrate and anaerobic oxidised carbohydrate is the amount of ATP produced. (thirty-four ATP in the aerobic oxidised carbohydrate versus two ATP in the anaerobic one)
  • Therefore for high-intensity, we need to get our energy from just those two ATP per glucose molecule. We can see that the demand for glucose is much higher.
  • It means that after you need to increase the carbohydrates consumed. That is why working with a nutritionist is beneficial for most athletes.
  • As a coach, I feel I am like a mechanic. I understand the athlete's physiology, and I can say what we need to do to improve. But everything related to nutrition, I have all my athletes working with a dedicated nutritionist. That takes some of the burdens out of me because I am not as expert as she is. Working with a nutritionist also gives the athlete another person to get more knowledge.
  • After long, more demanding sessions, the energy you burnt start to reflect the general needs. Based on the energy burnt and the metabolic-basal rate, you can calculate your needs. So you can be in an isocaloric state and maintain body weight (and muscle mass).
  • Of course, you need to keep your protein intake pretty steady during the day. The reason is this avoids muscle mass loss.

Ryan Bolton: nutrition general recommendations

1:20:20 -

  • I have a traditional view of nutrition. I believe in a periodised plan for nutrition as you have for your training. I do that with my athletes regarding fueling.
  • During the base phase, as intensity is significantly lower (a lot of zone one and two work), the need for sugar is reduced.
  • We use sugar as a fuel source, predominantly at higher intensities.
  • During base sessions, you should not use a lot of sugar. For many athletes, not taking sugar allows them to keep the intensity a bit lower. They want to go faster. But it is not the time of the season to go faster.
  • This phase emphasis is more on carbohydrate-restricted sessions and eating less during sessions. It means not adding fuel to workouts for long periods. The reason is to try to work on fat metabolism and training that system.
  • Looking at what getting fit means, it is ultimately becoming more efficient at burning fat at higher intensity levels.
  • As you get into the higher intensity work, start gradually adding fuel (sugars or complex sugars) to get the gut adapted to what happens during the races. It is also necessary because, with more intensity, you need more sugar. That is the only way you will have successful and high-quality workouts.
  • I am a believer in teaching your body not to be reliant on sugar. However, I also believe that sugar is a powerful fuel source to go harder. It allows you to work on that high end, top quality work.
  • There is a balance, of course. You cannot focus only on one aspect. And people can only consume a certain amount of calories before starting to have gut problems.
  • So, gradually adding sugar when approaching race season is fundamental.

Ryan Bolton: fueling guide for age groupers in different periods of the season

1:25:25 -

  • Fueling in different periods of the season varies a lot.
  • As you build the volume, the body should become adapted as well. If you go for a two hours bike ride, you will end pretty hungry if you have not been training for a while and do not eat. 
  • However, as you gain fitness, you perceive that you feel less hungry after such sessions. And in that way, you can go longer without feeling the need to eat. As long as you are keeping yourself in the correct zones, you should see a progression in the distance you can go with no or little fuel.
  • Therefore, during the base season, eat as little as possible. (only eating if you need it)
  • The type of fuel during the base phase also changes. If you need to take something for a five hours training ride, you do not need to take pure sugar (gel or something like that).
  • You can have a peanut butter and jelly sandwich or something that has more protein.
  • As you get into the more specific training (four or five weeks from the race), I like to move my athletes to train with the same race nutrition strategy.
  • Eating the exact type of things they will eat during the race. And also in equal quantities. That varies much from athlete to athlete.
  • It depends on their metabolism, stomach, their size. In Ironman, athletes might range from 250 to 600 kcal per hour. 
  • Athletes might say that they were having a good race until they started having gut problems. However, the problem is that they were probably pushing too hard, so the gut shuts down. But if you look at age groupers and the intensities they perform, it is lower than what the professionals are pushing.
  • The higher-end athletes that are pushing the limits are usually the professionals. They are more efficient, but they are also pushing harder. Therefore, they have to tap more into those sugar stores.
  • When you are at a period where the intensity starts to kick up, the athlete cannot get the calorie level of intake, as when closer to the race season. When my athletes begin to have more intensity, they need to start the fueling program. (on runs above one and a half hours)
  • Also, if they have bike rides above three hours with intensity, they need to start the fueling program.
  • A fueling program consists of eating during a workout from the start. Usually, the athletes start fueling twenty minutes into the training. Or they can even begin in advance.
  • The reason is that, for me, the athletes have the fuel to get to the end of a session and still have the ability to produce quality work. Another reason is to have the race nutrition plan nailed down. Sometimes that takes a lot of time. 
  • There are people that, with one Ironman, perform perfectly nutrition-wise. But they implement it on another Ironman and have stomach issues.
  • I think athletes must learn the indicators in their bodies of when they might start to have stomach issues. Learn what to do or how to back off in those moments is crucial to succeeding in the race. Or even the opposite. Evaluate if they are under-fueled. And what and how I should take new calories.
  • I think the glucose monitors are super valuable. Until this point, athletes have been evaluating themselves by feel and experience. With the data of glucose monitors, you can understand that you are low on sugar right now. And I need to consume something. Or I do not need to take anything because my sugar levels are high.
  • Indeed, we are just talking about blood sugar. It does not represent your stores. But still, Those things could be valuable and will become more and more prevalent on the racecourse.
  • Seeing the Tour de France banning the glucose monitors shows us how powerful these devices can be. It means that the athletes can get a lot of information from it.
  • That is the beauty of triathlon: it embraces innovation, while cycling is more traditional and old-fashion. 

Ryan Bolton: what to eat during training

1:35:45 - 

  • During the base phase, you can use alternative sources. You can eat a ham sandwich. 
  • This year was the first year I did an Ironman, and I was training with another Ironman athlete in a six-hour training ride.
  • We stopped at a gas station, and he bought one of those convenient ham sandwiches (probably not too good to you). He told me that I would be surprised by how good he will feel by hour five. What he was doing was taking calories.
  • On those rides, you do not need the pure sugar calories. We can afford to take more long term calories like complex carbohydrates. Or Even take protein and fat. 
  • During the base season, you can get away with that if you are taking calories. In this phase, I avoid gels, sugars and stuff like that. You do not need that type of stuff.
  • Some people choose not to eat in long workouts. It might work as long as you are not bonking.
  • The value of eating on those long rides (eating more protein-rich foods) is the recovery potential if you are not eating straight after the session.
  • If you do a five-hour fasted ride in the base phase, it is crucial to eat something when you get home. Get something in the system right away for recovery purposes. It is fundamental because by not eating during or after, you will dig yourself into a hole.
  • Therefore, there is this balance of making sure you getting in enough calories. The takeaway is to avoid sugars during the base phase.

Ryan Bolton: what to eat after training

1:38:53 - 

  • With the post-workout fueling, protein should be a significant part of the equation. But sugars as well.
  • Therefore, I suggest making a smoothie. Use some juice, add some honey or pure glucose sugar to it. Top it with protein (protein powder). 
  • They say that the optimal ratio is 4:1, which is what chocolate milk presents. Maybe the optimal recovery food. 
  • As you get into the higher-intensity phases, that recovery food is fundamental. Particularly for triathletes doing more than one workout a day and doing consecutive days of hard sessions.
  • It is not as crucial for athletes that do one training per day. Or athletes that do not do high-intensity consecutive days. 

Ryan Bolton: tip for athletes with gut problems

1:40:14 -

  • When you enter the more intense and race seasons, people can have problems due to sensitive stomachs.
  • For those that have a hard time taking sugar in, taking the branch chain carbohydrates (UCAN) can help.
  • I believe in those kinds of products because you can preload a race situation or a workout situation. You will have a slow release of energy during these periods. 
  • And there is research showing it is a slow release of energy throughout the workout, enabling you to lighten the sugar load during the session. 
  • And I have athletes preloading for races, but even for training, I find that extremely valuable.
  • From feedback from athletes, it seems that Maurten also leads to some improvements in gut function.

Ryan Bolton: take-home messages

1:43:01 -

  • My take-home message is that we need to periodise nutrition.
  • I am not an extreme advocate, saying you should be in a caloric deficit all the time. Or the opposite, saying that you should constantly fuel with sugar.
  • That is why I believe the best approach is to periodise nutrition with the season and plan accordingly. It is not easy, but if you are interested in high performance, this is the best way to approach it.

Björn Kafka: general thoughts on workout fueling

1:44:59 -

  • First, when I start working with athletes, I try to find out if they have nutrition dogmas. (low-carb, keto, gluten-free) Any restrictive diet can make more harm than good. 
  • There can be some benefits for the athlete, but I have the feeling that it is more of a trend.
  • The next thing is eating in general. Especially in endurance sports is a problem. There is a lot more under-eating than "enough eating". There are body image and body weight problems like anorexia and stuff like that.
  • Eating enough is the goal, and then eating healthy, with easy things like fruits, vegetables or more fibre.
  • Fueling is the following step. What I see daily on my athletes is that they do not eat carbs enough during training. And I have to teach them how to do it better.
  • And they feel something magic. When they start eating more, they can hit the numbers and feel good, especially after the training.
  • Therefore, enough carbs pre, during, and post-workout is crucial for athletes.
  • The final point is meeting the daily protein requirements for the athlete.
  • With these points cleared out, I try to develop with them nutritional habits. I tell them how to fuel during the weeks of intensity and racing. (not only during workouts) 
  • The goal is that these habits become something regular in the athlete's lives.
  • I also address the athletes on how to eat during different weather conditions.
  • I see supplements and sports products as the icing on the cake. Before I start using supplements, the athletes need a strong foundation of what good nutrition is.
  • Sometimes I never do this with athletes because they do not get the "easy things" right. Even carb supplements (easy to digest), I only implement if the athlete understands nutrition.

Björn Kafka: fueling workout recommendations

1:49:49 -

  • What I do as a coach is analysing the power test I developed with Aerotune. It allows me to have an estimation of how much carbs the athlete needs at different intensities.
  • But it is not static because if the athlete performs high-intensity efforts, the amount of carbs changes.
  • And also, when you start a workout, the carbohydrate oxidation rate is different than after three hours.
  • Having these numbers (e.g. fifty grams of carbs at 260W) helps a lot. With this, the athlete gets sensible on his needs at different intensities.
  • Concerning what you should eat, one colleague of mine said nutritional science is very flexible. 50% is marketing, 40% voodoo science and maybe 10% actual science. And he is right in a sense. All these trends that appeared in the last years always seem to contradict past studies.
  • Therefore, we need to look back because of the influence of marketing.
  • When we do these tests, we get the Vo2Max and the VLaMax. And with these values, we can calculate the quantities of carbs and fats at different intensities in the test environment. (e.g. temperature twenty degrees Celcius)
  • The focus is also on drinking enough and on replenishing electrolytes. Especially when you have a drastic climate change. 

Björn Kafka: types of carbohydrates to consume during workouts

1:53:55 - 

  • It depends on the duration and intensity of the session.
  • To put it simply, the more intense the workout, the easier to digest the types of carbs should be.
  • Most of my athletes consume carbs in a liquid form. They buy ten kilos of maltodextrin and some fructose, and with their scale, put it in the bottles.
  • It is easy and cheap. It depends on how you tolerate the fructose. I personally also eat by feeling. If I feel a bit sick or not so well, I eat more. 
  • But most of the time, during easy rides, maltodextrin, fructose. And for longer rides, we start consuming protein (branch chain amino acids) to hit the daily protein requirements.
  • We do this because if you sit on the bike for twelve hours, you will not meet the protein requirements.

Björn Kafka: general rules of thumb for beginner athletes

1:57:27 -

  • For easy bike rides of around two hours, forty grams of carbs is a good number. It works with most athletes.
  • I always try to have a little bit more than too little. But if you are fifty kilos and not that fit, you might sustain thirty grams. But maybe taking a bit more will be helpful.
  • If you go to the mountains and are not well-trained, I would go sixty to seventy grams. (zone two or tempo ride)
  • Moreover, try to hit the nutrition goal a bit before. (e.g. if you know there is a mountain coming up to be easier to digest)
  • And if you race or have high-intensity sessions, ninety grams is what I recommend. Or even more, if you can tolerate it.
  • If you have a long session to do, it will depend on how well conditioned you are. Some athletes go with fifty grams with no problems for five hours.
  • But if you are not that fit and have heat weather, you will get fatigued and lose Vo2Max capacity. Therefore, you should consume more.
  • Depending on how well you ate the days before, you might do easy rides with no fuel. If you are total under-fueled for the last two days, you might only do forty-five minutes before bonking.
  • For an easy recovery ride for one to one and a half hours, you can do without fuel. And if you start eating after that period, it will not affect the oxidation of fats.
  • What you can also do is emptying your glycogen stores two days before the race. (during zone one/two rides)
  • But you should not do more than one and a half hours. We do not want you to bonk two days before the race.
  • However, I do not do it too often with my athletes. They have high training volumes that I only use because of the rebound effect of glycogen stores.

Björn Kafka: thoughts on carbohydrate depleted workouts 

2:01:50 - 

  • We do these sessions because of the rebound effect of the glycogen stores before the race.
  • What we do is doing a long ride three days before a race. We do not do it in a fasted state. But with a limited carb intake. Maybe just forty grams and do a five-hour ride.
  • Therefore, you feel weak after that. Then, you start eating six to seven grams of carbs per kg of body weight for the next three days. And you will be ready for the race.
  • Sometimes I do it to try to lower the VLaMax and becoming more efficient at burning fat. We could do it two to three weeks before a race (two to three times per week). But we do it very carefully and only with athletes with high VLaMax.
  • You do not want to sacrifice your digestive system, and especially the use of carbs.
  • If you digest only seventy grams of carbs per hour, that will be a mess during the race.
  • This training will not feel good. But sometimes, it works well. 

Björn Kafka: pre and post-workout fueling

2:04:03 -

  • The better the pre-fuel is, and the fuel during the workout, the less crucial is the post-workout meal. 
  • My idea of a good workout nutrition plan is to eat enough before the session to hit the number. 
  • Eat enough during the workout to have a good training session.
  • And eat enough to avoid craving food because of under-fueling.
  • You should finish the training with a good feeling. And then, having your recovery shake with sixty to seventy grams of carbs. It will depend on the intensity. You should also add twenty grams of protein.
  • After the recovery shake, we should start eating as usual. But of course, focusing on eating easy to digest food.
  • Always keep in mind how the training will be for the next few days.
  • If you are in a block of FTP training, where you burn a lot of glycogen, you should eat more carbs. The goal is that you can hit the number in future sessions.
  • If you are in a base phase, the carb intake is not as fundamental, and the focus should be more on fibre intake.
  • In the pre-workout meals, I like to develop some habits. When we do hard intervals, I enjoy implementing breakfast with low fibre and high carb content and doing it for four or five days to get used to it.
  • We also schedule the breakfast to be similar to the races. Eat three hours before the race.
  •  This breakfast has rice, maybe some MCT oil. This food was prepared the night before and left overnight. The goal is to have a different structure in the starch. The athletes might add then some jam.
  • The athletes would go training and then, focusing on eating the protein requirements. (two grams of protein per kg of body weight)

Björn Kafka: take home messages

2:08:55 -

  • Always or most times eat carbs during training. It is an eye-opener for athletes.
  • If you feel weak and you want to hit numbers, it is because you are under-fueled.
  • Many endurance athletes like the feeling of being "beaten down". (going to the limits and suffer)
  • Therefore, you can hurt yourself with low-carb training. You have the feeling of being empty. But workouts should not be like that.
  • You can also feel good and refreshed after training. It does not mean the session was not well executed.
  • If you are doing three weeks of intense training and you feel tired already, it is because you did something wrong. 
  • And in the second week, you will not hit the numbers, and the adaptations will not be the ones you want to get.

Mikael Eriksson: Overview and thoughts on workout fueling

2:11:14 - 

  • The fitter you are and the more you train overall, the more crucial workout fuel becomes.
  • It is the sum of only one workout but their integration in a training plan. (looking at the energy burnt over the weeks and months)
  • For very fit athletes with high training volume, you might need to fuel even short workouts. (e.g. an hour workout, where you will have other sessions later in the day)
  • So, fueling is a function of fitness and intensity, the overall power output, energy expenditure and training volume.
  • As a general rule of thumb, athletes should eat on workouts for ninety minutes or longer. 
  • And if the workout has a lot of intensity, I would say to fuel these as well. (even if they are shorter)
  • For longer and intense sessions, you will want to use what you consume during the workout. Therefore, eat sources of carbohydrates that are quickly absorbed. (gels, sports drinks or buying maltodextrin and fructose)
  • Depending on the duration of the workout and your sweat-sodium concentration, you might need to add electrolytes.
  • For longer workouts with low intensity, I am not against using sports nutrition products. But you have the option of using whole foods. (e.g. bananas or rice cakes)
  • The reason is that we are not concern about using the energy immediately in the workout. But we are making sure you start replenishing your glycogen while you are exercising. The goal is to avoid depleting yourself. In this way, you do not get depleted to the next workout.
  •  For short and intense workouts, you should use faster-acting fuels because your glycogen stores could get depleted. (even in a short period)
  • Therefore, you will use the sugar content in the maltodextrin or gels you take in a workout like that.
  • Regarding training low (carbohydrate-restricted training), I would not say it does not work. However, I have found it to be neutral or have negative impacts on performance.
  • It could work, but we have also to think about what other type of training we are not doing to do that restricted session. It is an opportunity cost.
  • These days, I am not using it much. I can try it with some athletes, but with an experimental mindset and evaluating the outcome. However, I do not expect it to work.
  • I am not against it. But comparing with other tools in the toolbox, I prefer using different methods.


Bernardo Gonçalves

Bernardo is a Portuguese elite cyclist and co-founder of SpeedEdge Performance, a company focused on optimising cycling and triathlon performance. He writes the shownotes for That Triathlon Show, and also produces social media content for each new episode.

{"email":"Email address invalid","url":"Website address invalid","required":"Required field missing"}

Explore our products and services