Nutrition Is the 4th Discipline: How Race Week and Race Day Fuelling Can Decide Performance
This weekend, athletes around the world will line up for major endurance events, including the T100 Triathlon World Tour, where the difference between a strong performance and a race that falls apart often comes down to something that happens long before the start line: nutrition.
In endurance sport, we often talk about the three disciplines — swim, bike and run — but there is a fourth discipline that supports every single one: fuelling.
You can have the best training plan, the strongest engine and the perfect race strategy, but if you do not have enough carbohydrate available to power your muscles, maintain intensity and support recovery, your performance potential is limited.
Nutrition is not something that happens after training. It is part of training. It is part of racing. It is part of becoming a more resilient athlete.
The athletes who perform consistently are not just the athletes who train the hardest. They are the athletes who learn how to fuel their bodies to handle the demands they are placing on them.
Race day is the final expression of everything that has happened in the weeks and months before. The training sessions, the recovery, the sleep, the meals and the fuelling practice all come together when the start line arrives.
The strongest athletes understand that nutrition is not an afterthought. It is a performance tool.
Athlete Carb needs are still below recommended levels
Recent research highlights that many endurance athletes still underestimate how much carbohydrate they are actually consuming during races.
A 2025 study by Lanpir et al. (European Journal of Sport Science) looked at carbohydrate intake during official endurance events and found that athletes consumed significantly less carbohydrate than they planned.
Across marathon runners and cyclists, actual carbohydrate intake averaged around 31.7g per hour, compared with planned intake of 38g per hour
This is why our carbohydrate-first Energy Bars are made with whole-food carbohydrate sources from cassava root and plantain fufu, providing approximately 38g of carbohydrates per bar to support training, racing and recovery.
The gap was not because athletes did not understand fuelling recommendations — many simply underestimated how much they were consuming, missed planned intake, or struggled to execute their strategy on race day.
The message:
A race fuelling plan only works if you practise it.
The impact of low carbohydrate availability on endurance performance
Carbohydrates are one of the most important fuels for performance.
Carbohydrate becomes increasingly important as exercise intensity rises. When athletes are racing, especially during long-course triathlon, marathon, cycling and ultra-endurance events, the ability to maintain pace, power and concentration depends heavily on carbohydrate availability.
Research from Jeukendrup (2014) highlights the importance of carbohydrate intake during exercise and how matching carbohydrate availability with exercise demands can support endurance performance. Carbohydrates help maintain blood glucose levels, support muscle glycogen stores and delay fatigue during prolonged exercise.
The conversation around endurance nutrition has changed significantly. The goal is no longer simply about eating less, losing weight or restricting carbohydrates. The focus is now on carbohydrate availability — having enough fuel available at the right time to meet the demands placed on the body.
Going into a race under-fuelled is not a strategy. It is a performance and health risk.
Low carbohydrate intake before or during endurance events can reduce glycogen availability, which may affect pacing, power output and the ability to maintain race intensity. This becomes especially important during events where athletes are working for several hours and need to repeatedly produce effort.
The goal is not to eat as much as possible.
The goal is to fuel appropriately for the work required.
Why carbohydrate matters before, during and after racing
Carbohydrate is stored in the muscles and liver as glycogen. These stores act as a fuel reserve that athletes rely on when intensity increases.
During endurance events, carbohydrate intake helps maintain energy availability and prevents athletes from reaching the point where performance drops dramatically.
Hearris et al. (2022) investigated high carbohydrate intake during exercise and demonstrated the ability of athletes to use carbohydrate from different delivery formats, supporting the current approach that athletes should practise carbohydrate fuelling strategies before race day.
For many endurance athletes, recommendations sit around 30–60g carbohydrate per hour during sustained exercise, with experienced athletes able to train their gut to tolerate higher intakes of around 60–90g per hour during prolonged events.
However, this is not something athletes should suddenly attempt on race day.
The gut is trainable.
Just like muscles adapt to training, the digestive system can adapt to receiving carbohydrate during exercise. This is why race fuelling needs to be practised during training.
The best race nutrition strategy is the one you have already tested.
Race week is about preparation, not restriction
Race performance is not created on race morning.
It is built through months of training, but race week is where athletes can either support their preparation or undermine it.
One of the biggest mistakes athletes make is reducing carbohydrates in the days before a race because training volume has decreased.
However, tapering training does not mean tapering fuel.
The purpose of race week is to maximise glycogen stores, support recovery and arrive at the start line with confidence.
Carbohydrate-rich foods such as rice, potatoes, pasta, oats, bananas, bread, cassava and plantain can all play an important role during race preparation.
The best approach is familiar foods that athletes already know they tolerate.
Race week is not the time for new diets.
It is not the time for carbohydrate restriction.
It is not the time to chase unnecessary changes.
It is the time to fuel.
RED-S, low energy availability and why fuelling matters beyond race day
Fuelling is not only about performance.
It is also about health.
Relative Energy Deficiency in Sport (RED-S) occurs when an athlete does not consume enough energy to support both exercise demands and normal physiological function.
This can happen when training increases but fuelling does not increase with it.
RED-S is not simply about body weight.
An athlete can look healthy while still being under-fuelled.
Low energy availability can affect hormones, bone health, immunity, recovery, mood, training adaptation and performance.
Williams et al. (1995) demonstrated that strenuous exercise combined with energy restriction could alter luteinising hormone secretion, showing the impact insufficient energy availability can have on hormonal function.
More recently, Salamunes, Williams and De Souza (2024) reviewed the relationship between energy availability and menstrual disturbances, highlighting the importance of understanding the relationship between fuelling, hormones and athlete health.
The message is simple:
The body needs enough energy to train, adapt, recover and perform.
You cannot build your best performance on an empty fuel tank.
Why carbohydrate diversity matters
RED-SCUE was built around the idea that athletes need practical carbohydrate-first fuelling.
The foundation of RED-SCUE bars is cassava and plantain fufu, two traditional carbohydrate sources used around the world.
Carbohydrate diversity matters because different carbohydrate sources provide different experiences for athletes, and finding options that work for your digestion, training and race demands is essential.
For some athletes, oats and bananas remain excellent fuelling choices. They are familiar, accessible and effective carbohydrate sources.
For others, especially athletes looking for different carbohydrate options, cassava and plantain provide another way to increase carbohydrate intake.
The focus is not replacing every traditional food.
The focus is giving athletes more options and more diversity.
Sleep, recovery and fuelling work together
Performance is never created by one factor alone.
Training, nutrition, recovery and sleep all work together.
Cook et al. (2023), investigating marathon runners from the 2016 London Marathon, explored the relationship between sleep health, lifestyle factors and marathon completion time.
Sleep is one of the most overlooked performance tools.
Poor sleep can influence recovery, appetite regulation, decision-making and overall readiness.
Greer et al. (2013) demonstrated that sleep deprivation can increase food desire and influence brain responses linked to food reward, showing how recovery and nutrition behaviours are connected.
Athletes often focus on the kilometres completed but forget that adaptation happens after training.
Training creates the stimulus.
Nutrition provides the building blocks.
Sleep allows adaptation.
Race week fuelling with RED-SCUE
A successful race nutrition strategy starts before the event.
The days leading into a race are about consistency, carbohydrate availability and confidence.
RED-SCUE Fuelling Jars can be used as a simple carbohydrate-focused breakfast option during training and race week.
A Vanilla or Cacao Fuelling Jar provides a convenient option for athletes who want a familiar breakfast that supports carbohydrate intake without unnecessary complexity.
A race week morning could include a RED-SCUE Fuelling Jar with additional fruit, oats or toast depending on personal preference.
For athletes who prefer traditional options, oats with banana, toast with jam or rice-based breakfasts can also work well.
The key is choosing foods that have already been tested.
Morning, afternoon and evening race week fuelling
During race week mornings, the focus should be carbohydrate availability and preparation.
A RED-SCUE Fuelling Jar, oats, banana, toast or another familiar carbohydrate-based breakfast can help athletes begin the day fuelled.
If training during race week, a RED-SCUE Vanilla Cinnamon bar can provide a simple pre-training carbohydrate option.
Vanilla Cinnamon is designed as the straightforward choice before training or racing when athletes want easy carbohydrate without overcomplicating digestion.
In the afternoon, athletes often underestimate their fuelling needs.
Travel, race registration, kit preparation and nerves can make it easy to forget to eat.
This is where having convenient carbohydrate options available can make a difference.
A RED-SCUE bar between meals can help maintain carbohydrate intake and prevent athletes arriving at dinner already depleted.
Different flavours can support different preferences.
Salted Caramel is a popular option when athletes want a richer flavour and can fit into longer sessions where sodium intake is also being considered.
Lemon Drizzle provides a lighter, refreshing option alongside hydration and electrolyte strategies.
Orange Zest offers a bright flavour profile during longer training days or race preparation.
Chocolate Chip provides a familiar option while still supporting carbohydrate intake with magnesium for nightime.
In the evening, race week meals should focus on carbohydrate, recovery and familiarity.
Rice, pasta, potatoes and other carbohydrate-based meals alongside protein and fluids can support glycogen restoration and recovery.
The night before racing is not about perfection.
It is about confidence.
The best race meal is usually the one you have practised.
Race morning fuelling timeline
Race morning starts before the start line.
Three to four hours before racing, athletes should aim for a carbohydrate-based breakfast.
This could include a RED-SCUE Fuelling Jar, oats, banana, toast with honey or jam, or another familiar carbohydrate source.
The aim is to begin the race with topped-up glycogen stores while allowing enough time for digestion.
Around 60–90 minutes before the start, a RED-SCUE Vanilla Cinnamon bar can provide an easy carbohydrate top-up.
Around 15–30 minutes before racing, some athletes may choose an additional small carbohydrate source depending on personal preference and tolerance.
The rule remains the same:
Nothing new on race day.
Fuelling during T100 and long endurance events
Events such as T100 demand careful fuelling because athletes are racing for several hours across multiple disciplines.
During long-course events, carbohydrate intake needs to be planned before fatigue arrives.
Many athletes make the mistake of waiting until they feel tired before fuelling.
By then, performance may already be affected.
The bike is often the easiest place to consume carbohydrate because the body is under less mechanical stress compared with running.
This is where athletes can strategically use products such as RED-SCUE bars alongside fluids and other carbohydrate sources (measured to fit your jersey, tri suit, saddle bag, or run vest and belt.)
A possible approach could include:
Starting with Vanilla Cinnamon early when simple carbohydrate and easy digestion are the priority.
Moving towards Salted Caramel during longer periods where flavour variety and sodium considerations matter.
Using Lemon Drizzle or Orange Zest when athletes want lighter flavours during prolonged racing.
Choosing Chocolate Chip or Cacao later in the event when athletes want a familiar taste and carbohydrate boost.
The best strategy is individual.
Some athletes prefer gels.
Some prefer drinks.
Some prefer real-food carbohydrate options.
The important factor is consistency and practice.
Protecting the gut during endurance racing
Gastrointestinal issues are one of the biggest challenges in endurance sport.
Research by de Oliveira, Burini and Jeukendrup (2014) examined gastrointestinal complaints during exercise and highlighted how factors such as exercise intensity, nutrition choices and individual tolerance influence digestive comfort.
The answer is not always reducing carbohydrate.
Often, the answer is practising.
The gut adapts.
Athletes who practise fuelling strategies in training are more prepared for race day.
The psychology of competition
Competition changes the physical and psychological demands placed on athletes.
Cooke et al. (2011) explored the effects of competition on endurance performance and the underlying psychological and physiological mechanisms.
Confidence comes from preparation.
Knowing what you will eat, when you will fuel and what your body tolerates removes uncertainty.
Nutrition becomes another part of the race plan.
The final discipline
The swim requires skill.
The bike requires power.
The run requires endurance.
But all three depend on the fourth discipline.
Nutrition.
Whether you are racing the T100, a marathon, an ultra, a cycling event or your first endurance challenge, performance begins before the start line.
The strongest athletes are not simply the ones who train harder.
They are the ones who recover better, fuel consistently and arrive ready to perform.
Arrive fuelled.
Stay fuelled.
Perform at your best.
Swim. Bike. Run. Fuel.
Nutrition is the fourth discipline.
References
Cook JD, Gratton MKP, Bender AM et al. (2023). Sleep Health, Individual Characteristics, Lifestyle Factors, and Marathon Completion Time in Marathon Runners: A Retrospective Investigation of the 2016 London Marathon. Brain Sciences.
Cooke A, Kavussanu M, McIntyre D, Ring C. (2011). Effects of Competition on Endurance Performance and the Underlying Psychological and Physiological Mechanisms. Biological Psychology.
de Oliveira EP, Burini RC, Jeukendrup A. (2014). Gastrointestinal Complaints During Exercise: Prevalence, Etiology, and Nutritional Recommendations. Sports Medicine.
Greer SM, Goldstein AN, Walker MP. (2013). The Impact of Sleep Deprivation on Food Desire in the Human Brain. Nature Communications.
Hearris MA, Pugh JN, Langan-Evans C et al. (2022). 13C-Glucose-Fructose Labeling Reveals Comparable Exogenous CHO Oxidation During Exercise When Consuming 120g/h in Fluid, Gel, Jelly Chew, or Coingestion. Journal of Applied Physiology.
Heikura IA, Burke LM, Mero AA et al. (2017). Dietary Microperiodization in Elite Female and Male Runners and Race Walkers During a Block of High Intensity Precompetition Training. International Journal of Sport Nutrition and Exercise Metabolism.
Jeukendrup A. (2014). A Step Towards Personalized Sports Nutrition: Carbohydrate Intake During Exercise. Sports Medicine.
Jiménez-Alfageme R et al. (2025). Nutritional Intake and Timing of Marathon Runners: Influence of Athlete’s Characteristics and Fueling Practices on Finishing Time. Sports Medicine Open.
Lanpir AD, Eroğlu MN, Özyıldırım M, Louis J. (2025). Under Consumed and Overestimated: Discrepancies in Race-Day Carbohydrate Intake Among Endurance Athletes. European Journal of Sport Science.
Salamunes ACC, Williams NI, De Souza MJ. (2024). Are Menstrual Disturbances Associated with an Energy Availability Threshold? A Critical Review of the Evidence. Applied Physiology, Nutrition, and Metabolism.
Williams NI et al. (1995). Strenuous Exercise with Caloric Restriction: Effect on Luteinizing Hormone Secretion. Medicine & Science in Sports & Exercise.
