The final week before a race can feel surprisingly stressful. Training volume may be decreasing, but there are still meals to plan, medications to organize, sleep schedules to manage, and last-minute worries about whether everything will go smoothly.
For runners, cyclists, triathletes, and other endurance athletes, race-week health involves more than avoiding injury. Poor sleep, unfamiliar foods, digestive symptoms, dehydration, illness, and medication decisions can affect both safety and performance. A plan that worked during ordinary training may also need adjustments when travel, early start times, unfamiliar weather, and race-day nerves enter the picture.
The goal is not to control every detail or eliminate uncertainty. It is to arrive at the starting line rested, adequately fueled, medically prepared, and familiar with the routines you intend to use.
This guide explains how to approach sleep, gastrointestinal symptoms, hydration, medication safety, and race-day health decisions during the final week before an endurance event.
Why Race Week Needs a Different Health Strategy
During training, athletes gradually build fitness by challenging the body and allowing time for adaptation. During race week, the emphasis shifts toward maintaining readiness while reducing unnecessary fatigue and avoiding preventable problems.
Common challenges include:
- Reduced sleep because of travel, excitement, or anxiety
- Changes in meal timing and food choices
- Stomach discomfort from exercise or pre-race nerves
- Trying unfamiliar energy gels, sports drinks, or supplements
- Using pain relievers to manage soreness
- Forgetting medications or changing their timing
- Exposure to illness during travel or crowded events
- Adjusting to heat, humidity, altitude, or unfamiliar terrain
The CDC identifies inadequate sleep, dehydration, and insufficient nutrition as factors that can increase health risks during physically demanding activities and adventure travel.
Race week is therefore a time for consistency rather than unnecessary experimentation.
Start With a Seven-Day Health Check
Before focusing on pace or finish time, review how your body is functioning.
Ask yourself:
- Am I sleeping reasonably well?
- Have I developed fever, respiratory symptoms, vomiting, or diarrhea?
- Am I recovering normally from recent training?
- Do I have a new injury or worsening pain?
- Are my usual meals and hydration routine working?
- Do I have enough prescription medication for the event and travel?
- Are there medical symptoms that need attention before racing?
This check is particularly important for athletes with diabetes, asthma, heart disease, gastrointestinal conditions, or other chronic health concerns.
Changes in symptoms may be more important than a single training metric or wearable recovery score.
Sleep: Prioritize the Entire Week
Sleep supports physical recovery, attention, reaction time, emotional regulation, and general health. These benefits matter during endurance training and competition.
According to the CDC, adults ages 18 to 60 generally need at least seven hours of sleep per night, although individual needs vary.
During race week, aim for adequate sleep across several nights rather than relying on one unusually long night immediately before the event.
Practical steps include:
- Keep bedtime and wake-up times relatively consistent.
- Allow enough time for your usual sleep needs.
- Reduce late-night work, packing, and unnecessary commitments.
- Avoid unusually late caffeine intake.
- Limit alcohol, especially close to bedtime.
- Keep the sleeping environment dark, quiet, and comfortable.
- Prepare equipment earlier in the week to reduce last-minute stress.
Sleep cannot be forced, but predictable routines make it easier to protect.
What if You Sleep Poorly the Night Before the Race?
Pre-race nerves, early alarms, travel, and unfamiliar sleeping environments can make the final night difficult.
One short night does not automatically mean a race will go badly. However, significant sleep deprivation can affect attention, judgment, perceived effort, and physical readiness.
If sleep is difficult:
- Avoid repeatedly checking the clock.
- Keep the room quiet and comfortable.
- Use familiar relaxation strategies.
- Stay with your planned morning routine.
- Consider adjusting pacing expectations if you feel unusually fatigued.
Do not compensate for poor sleep by taking excessive caffeine, experimenting with sedatives, or using unfamiliar energy products.
Severe sleepiness, dizziness, or impaired alertness can also make driving or cycling to an event unsafe.
Should You Use Sleep Medication Before a Race?
Trying a new sleeping pill or supplement immediately before competition can create unexpected problems.
Some prescription and over-the-counter sleep aids may cause next-day drowsiness, dizziness, impaired coordination, or changes in alertness.
Even products marketed as natural may interact with other medications or affect sleep differently from person to person.
If you already use a prescribed sleep medication, continue according to your clinician's instructions unless they advise otherwise.
Ask a clinician or pharmacist before introducing a new sleep aid, particularly if you have sleep apnea, take other sedating medications, or need to drive early in the morning.
Why GI Symptoms Are Common in Endurance Events
Digestive symptoms are common in endurance sports, particularly running and long-duration events.
During strenuous exercise, blood flow is redirected toward working muscles and the cardiovascular system. Heat, dehydration, movement-related mechanical stress, nutritional choices, and exercise intensity may also contribute to gastrointestinal discomfort.
Symptoms can include:
- Nausea
- Stomach cramping
- Bloating
- Acid reflux
- Urgent bowel movements
- Diarrhea
- Vomiting
- Difficulty tolerating sports drinks or energy gels
A 2025 joint position statement from Sports Dietitians Australia and the Ultra Sports Science Foundation describes exercise-associated gastrointestinal symptoms as a common challenge for endurance athletes and emphasizes individualized nutrition and symptom-management strategies.
Why Race-Day Nerves Can Affect Digestion
The digestive system communicates closely with the nervous system. Stress and anxiety can influence intestinal movement, stomach sensations, and bowel urgency.
Some athletes experience loose stools or nausea before an event even when they tolerate similar exercise during ordinary training.
Possible contributors include:
- Anticipatory anxiety
- Earlier-than-usual breakfast timing
- Changes in caffeine intake
- Eating too quickly
- Rushing to the starting area
- Changes in hydration or meal composition
A consistent morning routine can reduce uncertainty, although it cannot eliminate every digestive symptom.
Allow sufficient time for waking, breakfast, bathroom access, transportation, and equipment preparation.
Keep Pre-Race Foods Familiar
The final days before an event are not the ideal time to test a new breakfast, energy gel, carbohydrate powder, or high-fiber nutrition plan.
Sports Dietitians Australia recommends practicing competition nutrition during training and choosing pre-event foods that are familiar, easy to digest, and appropriate for the exercise demands.
Before the race:
- Use meals you have tolerated during long training sessions.
- Avoid unusually large meals immediately before exercise.
- Keep portion sizes appropriate for the time available before the start.
- Be cautious with high-fat or very high-fiber meals if they trigger symptoms.
- Use a familiar carbohydrate source.
- Stick with practiced sports drinks and fueling products.
The ideal meal differs across athletes. Someone with IBS, diabetes, food allergies, or another medical condition may need a personalized strategy.
Does Reducing Fiber Help Before a Race?
Some runners with a history of urgent bowel movements, bloating, or diarrhea find that temporarily reducing certain high-fiber foods before competition improves comfort.
This does not mean fiber is unhealthy or that every athlete should follow a low-fiber diet.
For susceptible athletes, foods that may cause symptoms include:
- Large servings of beans or lentils
- Very high-fiber cereals
- Large raw salads
- Some high-fiber vegetables
- Large quantities of dried fruit
- Foods containing certain sugar alcohols
Sports Dietitians Australia's pre-event nutrition guidance identifies lower-fiber carbohydrate foods and changes in meal timing as strategies that may help athletes prone to gastrointestinal discomfort.
Temporary adjustments should be based on personal tolerance and ideally tested during training. Long-term dietary restriction without a clear reason can unnecessarily reduce nutritional variety.
Be Careful With New Carbohydrate Gels and Sports Drinks
Concentrated carbohydrate products can be useful during prolonged endurance activity, but gastrointestinal tolerance varies.
Problems may arise when an athlete suddenly increases carbohydrate intake, uses unfamiliar products, or combines several highly concentrated sources without adequate fluid.
Before race day, confirm:
- Which products you have used successfully during training
- How often you normally consume them
- Whether you tolerate their carbohydrate concentration
- How much fluid you usually drink with them
- Whether the race provides the same products
- Whether caffeine or other added ingredients cause symptoms
If the event supplies an unfamiliar sports drink, consider carrying familiar products when permitted.
Gut training during earlier training phases may improve tolerance for some athletes, but major increases in carbohydrate intake should not be attempted for the first time during competition.
Hydration: Avoid Both Too Little and Too Much
Dehydration can contribute to fatigue, dizziness, overheating, and gastrointestinal discomfort.
However, drinking excessive amounts of fluid can also be dangerous, particularly during prolonged endurance events.
Exercise-associated hyponatremia occurs when blood sodium becomes abnormally low during or after exercise, often associated with excessive fluid intake relative to losses.
Athletes should not assume that drinking as much water as possible is the safest strategy.
Sports Dietitians Australia's position statement on exercise in hot environments emphasizes individualized fluid and electrolyte strategies based on event duration, intensity, climate, access to fluids, and gastrointestinal tolerance.
Use a hydration plan practiced during training, account for weather conditions, and avoid forcing excessive fluids.
Electrolytes Are Not a Guarantee Against Hydration Problems
Sodium-containing sports drinks and other electrolyte products can play a role during prolonged exercise, especially when sweat losses are substantial.
However, electrolytes do not make excessive fluid consumption safe.
Likewise, taking additional salt does not automatically prevent heat illness, dehydration, or hyponatremia.
Fluid and sodium needs depend on individual sweat characteristics, event conditions, exercise duration, and medical history.
Athletes with kidney disease, heart failure, high blood pressure, or medications affecting fluid and electrolyte balance should seek personalized medical guidance.
Medication Planning: Do Not Wait Until Race Morning
Medication planning is often overlooked because athletes focus mainly on fueling and equipment.
However, prescription medicines, over-the-counter pain relievers, allergy products, inhalers, and supplements may affect hydration, alertness, blood pressure, blood glucose, digestion, or exercise tolerance.
Before race week, review:
- Prescription medications
- Over-the-counter pain medicines
- Allergy and cold medicines
- Sleep aids
- Caffeine-containing products
- Sports supplements
- Medications used as needed
Do not stop, delay, double, or change prescribed medications simply to improve race performance without discussing the decision with the prescribing clinician.
NSAIDs: Why Pre-Race Pain Relief Can Be Risky
Nonsteroidal anti-inflammatory drugs, or NSAIDs, include ibuprofen and naproxen.
Some athletes take these medications before or during races hoping to prevent soreness or make an injury easier to tolerate.
That approach can create unnecessary risks.
NSAIDs may affect kidney blood flow and increase the risk of gastrointestinal complications. These concerns can become more important during prolonged exercise, dehydration, heat exposure, or illness.
A randomized trial involving ultramarathon runners found a higher observed rate of acute kidney injury among participants receiving ibuprofen compared with placebo, although the study's confidence interval included uncertainty about the magnitude of the difference.
Do not use NSAIDs preventively to mask pain before or during an endurance event. If you need pain medication to participate, ask a clinician whether racing is appropriate and which treatments are safest.
What About Acetaminophen?
Acetaminophen is not an NSAID and does not have the same anti-inflammatory effects.
However, it is not automatically a risk-free alternative.
Taking more than the recommended dose can cause serious liver injury. Acetaminophen is also included in many combination cold, flu, and prescription pain medicines.
It should not be used to conceal symptoms of illness or injury in order to compete.
If you need medication for pain or fever during race week, discuss the underlying reason rather than focusing only on symptom suppression.
Diabetes Medications and Race-Day Fueling
People with diabetes may need additional planning because prolonged exercise can affect blood glucose during and after activity.
Insulin and some glucose-lowering medications can increase the risk of hypoglycemia, while illness, stress, and inadequate insulin may contribute to hyperglycemia.
Important planning considerations include:
- Blood glucose monitoring during prolonged activity
- Access to rapid-acting carbohydrates
- Insulin timing and delivery equipment
- Continuous glucose monitor reliability and backup supplies
- Ketone testing when clinically indicated
- Managing delayed hypoglycemia after exercise
- What to do if illness or vomiting interferes with food intake
Discuss event-specific medication and fueling plans with the diabetes care team well before race day.
Do not use another athlete's insulin or carbohydrate strategy as a substitute for individualized medical instructions.
Asthma and Respiratory Medication Planning
Cold air, pollen, smoke, exercise intensity, and respiratory infections may trigger breathing symptoms in susceptible athletes.
If you have asthma, make sure your treatment plan is current and your prescribed inhalers are available.
Review:
- Whether symptoms are adequately controlled
- Inhaler technique
- Medication availability and expiration dates
- Known environmental triggers
- Instructions for exercise-related symptoms
- When breathing difficulty should prevent participation
Do not rely on an inhaler to push through severe or unexplained breathing difficulty.
Worsening asthma symptoms during race week warrant medical review.
Blood Pressure, Heart Medications, and Heat
Some cardiovascular medications can affect heart rate, blood pressure, fluid balance, or responses to exercise.
Examples include certain beta blockers, diuretics, and blood pressure medications.
For athletes taking these medicines, heart-rate-based training zones may not always reflect exercise intensity in the usual way.
Heat exposure and dehydration can also complicate medication-related blood pressure changes.
Discuss medication timing, hydration limits, symptoms of low blood pressure, and safe exercise intensity with the treating clinician.
Do not independently stop cardiovascular medications before competition.
Traveling to a Race With Prescription Medications
Travel can introduce missed doses, lost luggage, temperature-related storage problems, or confusion about medication timing.
The CDC recommends carrying essential medication in hand luggage, keeping medicines in original labeled containers, and bringing enough for the trip plus additional supplies for unexpected delays.
A race travel checklist may include:
- Current prescriptions
- Medication list with doses
- Backup supplies when appropriate
- Glucose monitoring or insulin equipment
- Prescribed inhalers
- Emergency medications
- Storage instructions
- Clinician contact information
International events may require additional planning because certain prescription medications are regulated differently across countries.
Caffeine: More Is Not Always Better
Caffeine can improve performance in some endurance activities, but tolerance varies.
Potential problems include:
- Sleep disruption
- Anxiety or jitteriness
- Palpitations
- Nausea or reflux
- Urgent bowel movements
- Interactions with other stimulants or medications
Race week is not the time to test unusually high caffeine doses or combine several products without calculating total intake.
If you routinely use caffeine during training, stick with a familiar approach and consider your medical history.
People with certain arrhythmias, anxiety disorders, gastrointestinal conditions, or other relevant concerns may need individualized guidance.
Supplements: Avoid Last-Minute Additions
Race expos and social media advertisements frequently promote products claiming to improve endurance, recovery, hydration, or focus.
Potential ingredients include stimulants, herbal extracts, concentrated electrolytes, amino acids, and combinations that may not have been tested together.
During race week:
- Avoid unfamiliar pre-workout products.
- Do not introduce high-dose supplements without a clear reason.
- Review caffeine content across products.
- Consider medication interactions.
- Use independently tested products when supplements are appropriate.
- Do not assume natural ingredients are harmless.
For competitive athletes subject to anti-doping rules, supplement contamination and medication restrictions are additional considerations. Check the relevant sport's rules and seek qualified guidance when necessary.
What to Do if You Develop Diarrhea Before the Race
Not all pre-race diarrhea is caused by anxiety or exercise.
Possible causes include foodborne illness, viral infection, medication effects, dietary changes, or an underlying gastrointestinal condition.
If diarrhea develops, consider:
- Whether fever, vomiting, or abdominal pain is present
- Whether you can maintain normal food and fluid intake
- Whether symptoms are improving or worsening
- Whether other people who ate the same food are ill
- Whether there is blood in the stool
- Whether dehydration symptoms are developing
Persistent diarrhea, fever, bloody stool, or significant dehydration requires medical evaluation.
Do not use an anti-diarrheal medication to conceal severe symptoms and proceed with prolonged competition without medical guidance.
When It May Be Safer Not to Race
One of the most difficult decisions during race week is whether to withdraw or postpone participation.
Training investment, travel expenses, and personal goals can make athletes reluctant to change plans.
However, certain symptoms deserve medical assessment rather than attempts to push through.
- Fever or significant systemic illness
- Persistent vomiting or diarrhea
- Inability to maintain hydration
- Chest pain or unexplained shortness of breath
- Fainting or near-fainting
- New palpitations with concerning symptoms
- Severe or worsening injury
- Marked weakness or confusion
- Significant blood glucose or ketone abnormalities in a person with diabetes
A clinician can help determine whether participation is safe and whether further evaluation is needed.
Completing a race should never take priority over recognizing a potentially serious medical condition.
A Practical Race-Week Health Checklist
Use the following structure to organize the final week.
Five to Seven Days Before
- Protect sleep and recovery.
- Review prescription medications and supplies.
- Confirm the race-day fueling plan.
- Check expected weather conditions.
- Address persistent pain or concerning symptoms.
- Avoid introducing new supplements.
Two to Four Days Before
- Keep meals familiar.
- Adjust food choices based on known gastrointestinal tolerance.
- Maintain appropriate hydration without excessive fluid intake.
- Prepare medications and essential equipment.
- Plan transportation and bathroom access.
- Reduce unnecessary late-night commitments.
The Day Before
- Follow the practiced pre-race nutrition approach.
- Avoid excessive alcohol.
- Pack familiar fueling products.
- Review medications and emergency supplies.
- Confirm start time and travel arrangements.
- Allow adequate time for sleep.
Race Morning
- Use your familiar breakfast routine.
- Take prescribed medication as directed.
- Allow time for digestion and bathroom access.
- Follow the planned hydration strategy.
- Do not introduce unfamiliar pain medicines or supplements.
- Reassess symptoms before starting.
What to Track During Race Week
A short health log can help distinguish ordinary pre-race nerves from a developing medical problem.
- Sleep: approximate duration and quality
- GI symptoms: nausea, bloating, reflux, diarrhea, or cramps
- Meals: unusual foods or changes in timing
- Hydration: intake patterns and signs of dehydration or overdrinking
- Medications: doses, missed doses, and unexpected effects
- Energy: unusual fatigue or weakness
- Pain: new injuries or worsening symptoms
- Illness: fever, cough, vomiting, or other concerning changes
Use the information to make sensible decisions rather than attempting to optimize every measurement.
Common Mistake: Trying to Fix Sleep With a New Medication
Pre-race insomnia can be frustrating, but unfamiliar sleep aids may cause next-day side effects.
Protect sleep throughout the week.
Ask about medication safety before trying a new product.
Common Mistake: Changing the Diet at the Last Minute
Suddenly increasing carbohydrates, fiber, supplements, or concentrated sports drinks can worsen GI symptoms.
Follow a fueling plan practiced during training.
Make adjustments based on established tolerance rather than race-week trends.
Common Mistake: Taking NSAIDs to Prevent Pain
Taking ibuprofen or naproxen before a long race does not guarantee better performance and may increase kidney or gastrointestinal risks.
Do not use pain medication to conceal an injury.
Ask for medical evaluation when pain threatens participation.
Common Mistake: Drinking Excessive Water Before the Start
Overhydration can be dangerous during endurance exercise.
Use an individualized fluid plan.
Do not force large fluid volumes simply because race day is approaching.
Common Mistake: Changing Prescribed Medication Without Guidance
Stopping or adjusting medications may affect blood glucose, blood pressure, heart rhythm, breathing, or other aspects of health.
Review concerns with the prescribing clinician before race day.
Keep medications and important supplies accessible during travel.
Common Mistake: Ignoring Illness Because Training Is Complete
A completed training block does not make racing through illness safe.
Fever, persistent vomiting, serious respiratory symptoms, or unexplained cardiovascular symptoms warrant medical attention.
Postponing participation may be the safest decision.
When to Talk to a Clinician
Talk to a clinician before competition if you have persistent GI symptoms, unexplained fatigue, new pain, worsening asthma, unusual heart-rate changes, medication concerns, or a chronic health condition that may require exercise-specific planning.
You should also seek guidance if you develop repeated vomiting or diarrhea, significant sleep disturbances, recurring dehydration symptoms, or difficulty managing blood glucose during long training sessions.
A clinician may recommend medication review, sports nutrition counseling, laboratory testing when appropriate, assessment for gastrointestinal conditions, evaluation of an injury, or individualized exercise guidance.
For athletes taking prescription medications, a pharmacist may also help identify interactions between medicines, caffeine, supplements, and over-the-counter products.
When to Seek Urgent or Emergency Care
Seek emergency care for chest pain, severe breathing difficulty, fainting with concerning symptoms, sudden weakness or confusion, seizures, suspected heat stroke, or collapse during exercise.
Seek urgent medical evaluation for persistent vomiting, bloody diarrhea, severe abdominal pain, inability to maintain hydration, markedly reduced urination, or signs of significant heat illness.
Severe headache, confusion, repeated vomiting, or seizure during or after prolonged exercise may indicate a serious condition, including possible exercise-associated hyponatremia. These symptoms require emergency assessment rather than automatic treatment with more fluids.
Do not attempt to finish a race or return to competition after developing potentially life-threatening symptoms.
The Bottom Line
Race-week health is about protecting the preparation you have already completed. Sleep, digestive comfort, fueling, hydration, and medication safety deserve attention alongside equipment and pacing.
Prioritize adequate sleep throughout the week, use familiar foods and fueling products, prepare prescription medications in advance, and avoid preventive use of NSAIDs during endurance competition. Hydration should reflect your individual needs rather than an assumption that more fluid is always better.
The most common mistakes are trying new sleep aids, changing the diet at the last minute, taking pain relievers preventively, overdrinking water, changing prescribed medications without guidance, and ignoring signs of illness.
A successful race-week plan does not guarantee a personal best. It improves your chances of arriving prepared, recognizing problems early, and making decisions that protect your health. Sometimes the smartest race-day decision is adjusting the goal, slowing down, or not starting at all.
Medical disclaimer: This content is for informational purposes only and is not a substitute for professional medical advice, sports medicine evaluation, medication management, individualized nutrition counseling, diabetes care, cardiovascular assessment, gastrointestinal diagnosis, or emergency treatment. Always consult your physician, sports medicine clinician, registered sports dietitian, pharmacist, or qualified healthcare professional before changing prescribed medications, using pain relievers during endurance competition, introducing supplements, or racing with concerning symptoms. If you experience chest pain, severe breathing difficulty, collapse, loss of consciousness, seizures, severe confusion, suspected heat stroke, severe dehydration, exercise-associated hyponatremia symptoms, or another medical emergency, seek immediate medical care.