Mavr Sports Nutrition Team
Updated September 28, 2026. 9 min read.
Practice race nutrition in training by rehearsing your exact race fuel, timing, and hydration for at least 3-4 key sessions, progressively building toward 60-90 g carbs/hour and race-specific sodium and fluid targets.
If your race nutrition only exists on paper, it is not a race plan yet. It is a guess.
The athletes who avoid bonking and GI blowups do one thing consistently: they rehearse nutrition in training, under race-like stress, before race day.
Research in endurance nutrition consistently shows better performance and lower perceived effort when athletes execute practiced carbohydrate intake during prolonged exercise.
As sports nutrition researcher Asker Jeukendrup has emphasized: your gut is trainable. If you never train intake rate in workouts, race day is the worst time to attempt it.
Week 4 out
Carb Target45-60 g/hour
Session FocusTest products and early timing
Success MetricNo major GI distress
Week 3 out
Carb Target60-75 g/hour
Session FocusAdd sodium and fluid precision
Success MetricStable energy through final hour
Week 2 out
Carb TargetRace target (60-90 g/hour)
Session FocusFull dress rehearsal with race breakfast
Success MetricHit plan +/-10 g carbs/hour
Week 1 out
Carb TargetTaper-adjusted
Session FocusKeep routine familiar and simple
Success MetricZero new foods or products
| Week | Carb Target | Session Focus | Success Metric |
|---|---|---|---|
| Week 4 out | 45-60 g/hour | Test products and early timing | No major GI distress |
| Week 3 out | 60-75 g/hour | Add sodium and fluid precision | Stable energy through final hour |
| Week 2 out | Race target (60-90 g/hour) | Full dress rehearsal with race breakfast | Hit plan +/-10 g carbs/hour |
| Week 1 out | Taper-adjusted | Keep routine familiar and simple | Zero new foods or products |
If your race is 2 to 4 weeks away, compress the rehearsal into a 7-day race fueling challenge: test one race decision per workout and write down what your body tells you after each one. Aim to finish it at least 2 weeks before race day. Race week is for confirming the plan, not for new tests.
Day 1
What to TestRace breakfast at race timing
What to RecordFood, timing, stomach comfort, hunger at the start
Day 2
What to TestPre-start snack or top-up
What to RecordEnergy, heaviness, bathroom urgency
Day 3
What to TestCarbs during the workout
What to RecordCarbs per hour, gel timing, energy dips
Day 4
What to TestFluid volume
What to RecordAmount drunk, thirst, sloshing, urine color later
Day 5
What to TestSodium and electrolytes
What to RecordSalt marks, cramps, headache, thirst
Day 6
What to TestRecovery meal
What to RecordMeal timing, appetite, soreness, next-day energy
Day 7
What to TestFinal race-day checklist
What to RecordProducts, timing, backup options
| Day | What to Test | What to Record |
|---|---|---|
| Day 1 | Race breakfast at race timing | Food, timing, stomach comfort, hunger at the start |
| Day 2 | Pre-start snack or top-up | Energy, heaviness, bathroom urgency |
| Day 3 | Carbs during the workout | Carbs per hour, gel timing, energy dips |
| Day 4 | Fluid volume | Amount drunk, thirst, sloshing, urine color later |
| Day 5 | Sodium and electrolytes | Salt marks, cramps, headache, thirst |
| Day 6 | Recovery meal | Meal timing, appetite, soreness, next-day energy |
| Day 7 | Final race-day checklist | Products, timing, backup options |
If your race starts early, practice the early breakfast at least once, at your real race-morning wake-up time.
-3 to -4 hours
Pre-race meal
Target1-3 g carbs/kg body weight
0:20
First gel or drink carbs
Target20-30 g carbs
Each hour
Fuel and hydrate
Target60-90 g carbs + 400-800 ml fluid
Each hour
Electrolytes
Target400-800 mg sodium
Final 45-60 min
Optional caffeine dose
Target30-100 mg based on tolerance
| Time | Fuel Action | Target |
|---|---|---|
| -3 to -4 hours | Pre-race meal | 1-3 g carbs/kg body weight |
| 0:20 | First gel or drink carbs | 20-30 g carbs |
| Each hour | Fuel and hydrate | 60-90 g carbs + 400-800 ml fluid |
| Each hour | Electrolytes | 400-800 mg sodium |
| Final 45-60 min | Optional caffeine dose | 30-100 mg based on tolerance |
After your last rehearsal, write the whole plan down in one place so race morning is a routine, not a list of decisions.
The athletes who never have nutrition disasters on race day are not lucky — they have simply practiced fueling as deliberately as they practice pacing. Pick three or four key long sessions in the final weeks and run them as full rehearsals: the same pre-race breakfast, the same products at the same intervals, the same fluids. Keep a short log after each one noting energy, gut comfort, and what you would change. By race day your plan is not a hopeful theory; it is a routine your body has executed several times, and execution under fatigue feels familiar instead of risky.
Generating the session-by-session carb, fluid, and sodium targets and a race-morning checklist is something Mavr can build from your calendar. But the rehearsals and the notes are the part that actually removes the guesswork, and they cost you nothing but a few long runs done with intent.
At least 3-4 key long sessions should rehearse your exact race plan, including pre-race meal, in-session fueling, and hydration.
Most marathon athletes should practice in the 60-90 g/hour range, building up gradually according to gut tolerance.
Avoid switching if possible. If you must, test the replacement in at least one moderate session and lower risk by keeping total carb intake conservative.
Yes. Practice both dose and timing to confirm you get performance benefits without jitters or GI symptoms.
Mavr turns your training calendar into repeatable fueling targets and checklists so you can validate strategy before race day.
Treat it as useful data. Change one thing at a time, such as the product, carb amount, timing, fluid, sodium, or the meal before. If you change everything at once, you will not know what fixed the problem.
Yes. Beginners often have the most unknowns, so practice matters even more. Keep the first version simple: a tested breakfast, water, carbs for longer sessions, and a recovery meal afterward.
General guidance for healthy adults, not medical advice. Talk to a doctor or registered dietitian if you have a health condition, take medicines or have special dietary needs. Caffeine advice is for healthy adults only. EFSA's safe limit is 200 mg in one dose and 400 mg in a day.
Ask Mavr: "Create my race nutrition rehearsal for the next 4 weeks" and execute the plan below in your key long sessions.
Ask Kai, the coach in the app