Trained for months. Why do you feel flat on race morning?

You have done the work. Months of base. Weeks of specific training. The taper sat correctly. You went to bed early, slept seven hours, ate the same dinner you eat before every long run. Race morning, you wake up, eat your familiar breakfast, and arrive at the start line in textbook shape. Then your legs feel like concrete. The first 10 minutes are a battle. By 20 minutes, you are wondering what happened to all that fitness.

 

This is not a mental problem. It is a physiological one, and it is one of the most common and least understood experiences in endurance sport. You feel flat on race morning because your body is in a specific state that your training did not prepare for: post-fasting liver glycogen depletion, elevated cortisol, sympathetic nervous system overdrive, and a 60-minute pre-start window where most athletes do nothing while their cellular energy systems wait for instructions. This article walks through why each of these happens. The complete protocol for what to do about it sits in the Race-day nutrition guide. Here, the focus is the why.

 

What is actually happening to your body on race morning?

On race morning, your body is operating in a state that looks like fitness on paper but functions like fatigue in practice. Liver glycogen is depleted from the overnight fast. Cortisol is elevated above baseline because of anticipatory stress. The autonomic nervous system has shifted toward sympathetic dominance, often too far. And your cellular energy machinery has not yet been activated for sustained output. These four factors stack on top of each other.

The reason this state catches so many athletes by surprise is that training does not rehearse it. You train in the afternoon, mid-morning after breakfast, or in a fed state at the weekend. You almost never train at 7 a.m. with elevated cortisol, depleted liver glycogen, and the heart-rate jump that comes with being inside a corral of 5,000 other nervous athletes. Race-day physiology is its own state, and it has to be prepared for specifically.

 

What happens to your liver glycogen overnight?

During an overnight fast of 8 to 14 hours, liver glycogen drops by 50 to 80%. The classic study by Nilsson and Hultman, published in Scandinavian Journal of Clinical and Laboratory Investigation, showed that liver glycogen content in healthy adults declined from roughly 270 mmol per kg of liver after a normal evening meal to under 100 mmol per kg after a 10 to 14-hour overnight fast. Muscle glycogen stays largely intact unless you trained hard the day before, but muscle glycogen is not the issue. Liver glycogen is.

The liver's job during the first hour of exercise is to release glucose into the bloodstream to maintain blood sugar as your muscles start burning through their stored glycogen. With liver glycogen depleted, blood sugar can drop in the first 15 to 30 minutes of effort, especially at higher intensities. The feeling is exactly what you experience on a flat race morning: heavy legs, foggy head, breathing that feels harder than the pace warrants, and a sense that the engine is on but not in gear.

The race-week carb-loading protocol fills muscle glycogen but does not directly restore liver glycogen overnight. That is a job for the race-morning breakfast. Without that breakfast, or with an inadequate one, you start the race in a quiet metabolic hole that you spend the first few kilometres climbing out of.

 

Why does race-day cortisol make you feel worse, not better?

Cortisol rises every morning as part of the natural cortisol awakening response, peaking roughly 30 to 45 minutes after you wake up. On race morning, that natural rise is amplified by anticipatory stress. Research published in the Journal of Sports Sciences has shown that pre-competition cortisol levels can run 50 to 100% above an athlete's training-day baseline, with the effect strongest in less experienced racers.

Cortisol is a catabolic hormone. It shifts the body toward breaking things down rather than building things up. In a controlled training context, a short post-exercise cortisol spike is part of the adaptation signal. In a pre-race context, sustained high cortisol does the opposite of what you want. It promotes muscle protein breakdown over preservation, drives gluconeogenesis (the conversion of amino acids into glucose) at the expense of stored fuel use, suppresses immune function, and contributes to the jittery, distractible state most athletes recognise as "race nerves."

You cannot stop cortisol from rising on race morning. The trick is to keep it inside a productive range. A familiar morning routine helps. A calm warm-up environment helps. Tactical breathing in the final 10 to 15 minutes helps. Avoiding caffeine overdose helps (more caffeine on top of an elevated cortisol baseline can push you from activated into anxious). The goal is activation, not activation plus.

 

Why does your nervous system reduce blood flow to your muscles before a race?

The autonomic nervous system has two modes: parasympathetic (rest and digest) and sympathetic (fight or flight). Endurance performance requires a productive shift toward sympathetic activation. Race morning often pushes that shift too far. Sustained sympathetic overdrive, the state most athletes describe as "I felt nervous, not ready," does the opposite of what performance requires.

When sympathetic activation is appropriately tuned, blood flow redistributes toward working skeletal muscle, heart rate and stroke volume rise to meet demand, and the cardiovascular system pre-loads for the work ahead. When sympathetic activation tips into anxiety, blood flow shunts toward the periphery (skin, sweating preparation) rather than muscle, heart rate elevates unproductively while stroke volume stays low, and the body burns through fuel preparing for a fight that is not coming.

This is why the first 10 minutes of a race so often feel disproportionately hard. The cardiovascular system is in over-drive without being properly directed. Working muscles have not yet redirected blood flow toward themselves. The body has to spend the opening kilometres correcting the state it should have been in at the gun.

 

What is the 60-minute pre-race window, and why do most athletes waste it?

The 60 minutes before the gun is when each of these problems either gets addressed or compounds. It is the window in which liver glycogen can be partially restored, cortisol can be brought into a productive range, the nervous system can be primed toward activation rather than anxiety, and the cellular energy systems can be supported with the inputs they need. Most amateur athletes treat the window as a buffer for getting changed and standing in corrals. That is the gap.

What the window should contain: 30 to 60 g of easy carbohydrate to top up liver glycogen. Sips of fluid with a pinch of salt for hydration retention. A structured warm-up that raises core temperature and redirects blood flow toward working muscles. Brief tactical breathing to bring the autonomic nervous system into a productive state. And a pre-activity supplement that supports cellular energy production timed to peak as the gun goes off. For the full minute-by-minute breakdown, see the 60-minute pre-session protocol.

The other reason this window is wasted is that race-week stress reduces decision quality. By the time you are standing in a corral, you are not in a state to figure out a routine. The routine has to be built in training, repeated dozens of times before key sessions, and made automatic. Race week is not the time to invent the protocol.

 

How does the OLEUS Pre-Activity Shot address the gaps in this window?

The Pre-Activity Shot was designed for the specific physiological gaps the race-morning state creates. Each compound in the formula maps to one or more of the problems above. This is not a coincidence of formulation. It is why the product exists.

Liver glycogen and blood sugar: the shot contains 18 g of carbohydrate from sucrose, which delivers a fast-absorbing top-up of liver glycogen in the 45 to 60-minute window before the start. This works alongside, not instead of, the race-morning breakfast.

Cellular energy and mitochondrial readiness: the shot delivers 100 mg of Oleuropein from 500 mg of olive leaf extract for mitochondrial support, plus the full B-vitamin complex and 56.3 mg of magnesium as the enzymatic cofactors that ATP production depends on. This addresses the gap between "fitness in the bank" and "fitness available right now." For the underlying biology, see the Mitochondria guide.

Blood flow and oxygen delivery: 675 mg of L-citrulline supports nitric oxide production, which dilates blood vessels and improves the redirection of blood flow to working muscle. This counteracts the sympathetic-overdrive pattern of blood pooling at the periphery instead of being directed toward muscle.

Activation without anxiety: 80 mg of caffeine from 364 mg of Guarana extract. The dose is calibrated to support alertness and lower perceived exertion at the start without pushing an already elevated cortisol level into anxiety territory. The natural plant matrix of Guarana releases caffeine more gradually than an isolated synthetic dose, which fits the long arc of an endurance race better than a sharp stimulant peak.

Fatty acid utilisation: 375 mg of acetyl-L-carnitine supports the carnitine shuttle that moves fatty acids into the mitochondria for oxidation. For race efforts over 90 minutes, where fat becomes a meaningful fuel contributor, this supports the metabolic transition that the first hour of the race demands. The full label and per-ingredient research is in the Pre-Activity Shot ingredients article.

 

The flatness most athletes describe on race morning is not a mystery. It is the predictable outcome of four physiological gaps that compound in the final hour before the gun. We formulated the Pre-Activity Shot to address each of them inside the window where it matters.

OLEUS Performance Lab

What does the research show?

The OLEUS formula was evaluated in a placebo-controlled trial with 28 cyclists from a Switzerland-based World Tour professional cycling team, across a multi-day endurance protocol. The riders taking the formula showed +25% sustained power output over the test period compared to placebo. The trial measured the formula in race-relevant conditions, not in isolated ingredient assays. The point is the integrated effect across a multi-hour effort, which is exactly what a race-morning protocol is designed to support.

More than 5,000 endurance athletes across Belgium, the Netherlands, Switzerland, and beyond now use the OLEUS system. Athletes in the community frequently describe the dialled-in race-morning routine as the moment they realised cellular preparation matters as much as cardiovascular fitness.

 

Frequently asked questions

 

Why do I feel flat even when I sleep well before a race?

Sleep covers one of the four contributing factors (recovery and parasympathetic restoration) but not the other three. You can sleep perfectly and still wake up with depleted liver glycogen, an elevated cortisol response, and a nervous system that tips into anxiety before the gun. The race-morning state is its own physiology. Sleep is a prerequisite, not a solution.

 

Is it normal to feel sluggish for the first 20 minutes of a race?

It is common, but it is not unavoidable. The sluggish opening is the body correcting a state it should have been in at the gun. With a structured pre-race protocol covering nutrition, hydration, warm-up, nervous system priming, and the supplement window, the opening kilometres feel like the rest of the race, not a separate fight.

 

Should I eat breakfast earlier on race morning to avoid feeling flat?

The standard window is 3 to 4 hours before the start, which is also when most athletes already eat. Eating earlier than that risks the meal being fully digested and liver glycogen drifting down again by the gun. The fix is usually not earlier breakfast but better composition (1 to 4 g of carbohydrate per kg of body weight, low fat, low fibre) plus a 30 to 60 g carb top-up in the 60-minute window.

 

Does caffeine help with race-morning flatness?

Moderate caffeine helps. The International Society of Sports Nutrition position stand on caffeine and performance identifies 3 to 6 mg per kg of body weight as the ergogenic range, taken 45 to 60 minutes before exercise. High doses on top of an already elevated cortisol baseline can push you from activated into anxious. The Pre-Activity Shot delivers 80 mg of caffeine from Guarana, which sits below the upper end of the range deliberately for that reason.

 

How long does it take to dial in a race-morning routine?

Six to eight weeks of consistent rehearsal in training. The athletes who execute well on race day are the ones who have done the same routine before every key training session for months. The race-morning protocol is a habit, not a one-off. Race week is too late to design it.

 

The bottom line

You feel flat on race morning because four physiological gaps compound in the final hour before the gun. Liver glycogen is depleted. Cortisol is elevated. The nervous system has tipped into anxiety. Cellular energy production has not been primed. None of this is a mental problem. All of it is preventable with a structured pre-race protocol. The full guide is the Race-day nutrition guide. The shot built for the 60-minute window is below.

 

Sources

1. Nilsson, L.H., Hultman, E. (1973). Liver glycogen in man, the effect of total starvation or a carbohydrate-poor diet followed by carbohydrate refeeding. Scandinavian Journal of Clinical and Laboratory Investigation, 32(4), 325-330.

2. Heaney, J.L.J., Carroll, D., Phillips, A.C. (2014). Physical activity, life events stress, cortisol, and DHEA: preliminary findings that physical activity may buffer against the negative effects of stress. Journal of Aging and Physical Activity, 22(4), 465-473.

3. Goldstein, E.R., Ziegenfuss, T., Kalman, D., Kreider, R., Campbell, B., Wilborn, C., Taylor, L., Willoughby, D., Stout, J., Graves, B.S., Wildman, R., Ivy, J.L., Spano, M., Smith, A.E., Antonio, J. (2010). International Society of Sports Nutrition position stand: caffeine and performance. Journal of the International Society of Sports Nutrition, 7(1), 5.

4. Suzuki, T., Morita, M., Kobayashi, Y., Kamimura, A. (2016). Oral L-citrulline supplementation enhances cycling time trial performance in healthy trained men. Journal of the International Society of Sports Nutrition, 13, 6.

5. Burke, L.M., Hawley, J.A., Wong, S.H.S., Jeukendrup, A.E. (2011). Carbohydrates for training and competition. Journal of Sports Sciences, 29(sup1), S17-S27.

6. Hackney, A.C., Walz, E.A. (2013). Hormonal adaptation and the stress of exercise training: the role of glucocorticoids. Trends in Sport Sciences, 20(4), 165-171.

7. OLEUS placebo-controlled trial, 28 cyclists, Switzerland-based World Tour team, multi-day endurance protocol. Data on file, OLEUS Performance Lab.

This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.