Quick answer
- A half-marathon training nutrition plan should change by workout type.
- Easy runs usually need normal meals, quality workouts need carbohydrate before and after, long runs should practice race fueling, and race week should reduce surprises while keeping glycogen high.
- Mavr is built for this because it connects nutrition targets to the actual runs on your calendar instead of giving every day the same calorie goal.
4 key facts
- Half-marathon training includes easy runs, threshold sessions, long runs, rest days, and race rehearsals, and each needs a different nutrition decision.
- The biggest mistake is treating a half-marathon plan like a smaller marathon or a generic weight-loss plan.
- Workout timing matters: morning, lunch, and evening sessions need different meal placement.
- A training-aware nutrition app can use Runna, TrainingPeaks, Strava, or Apple Health context to adjust meals around the real week.
A half-marathon plan is short enough that many runners underfuel it and long enough that underfueling still ruins workouts. Your muscles store roughly 400-500 grams of carbohydrate as glycogen — enough for about 90 to 120 minutes of hard running before levels run low. Most half-marathon sessions sit right inside that window, which is exactly why fueling them sloppily for ten or twelve weeks adds up. The problem is rarely one bad breakfast. It is the slow accumulation of mediocre tempo runs, heavy-legged long runs, and recovery that never quite finishes because you ate the same way before all of them.
If you are training with Runna, TrainingPeaks, Strava, Apple Health, or a coach, the plan already separates a 40-minute recovery jog from a 6 x 1km threshold session. The energy cost of those two days can differ by 600 calories or more, yet most runners fuel them identically. Treating every day the same is the single most common reason a half-marathon block stalls.
The half-marathon nutrition mistake
Runners tend to fall into one of two traps. The first is eating like every run is race day — gels and sports drink for a 4-mile shakeout — which adds needless sugar and trains the gut for problems it does not have. The second, and far more common, is eating like every run is a calorie-burning errand to be minimized. A 35-minute easy run an hour after breakfast genuinely needs nothing extra. A 75-minute progression run after a full workday, finishing at 10K pace, is a different animal: start it on a depleted tank and you will run the last 15 minutes on fumes, miss the paces that make the session worthwhile, and recover slowly into the next day.
Fuel by workout type
Easy run (under 60 min)
Nutrition focusNormal meals; no gels needed. A light snack only if running early or fasted
Common mistakeForcing gels or skipping food to manufacture a deficit
Tempo or intervals
Nutrition focus30-60g carbs in the 1-2 hours before; 20-30g protein plus carbs within an hour after
Common mistakeTrying to hit threshold pace on an empty tank
Long run (75+ min)
Nutrition focusRehearse race breakfast, then 30-60g carbs per hour and 400-800ml fluid per hour
Common mistakeWaiting until race week to test fuel and fluids
Rest day
Nutrition focusSlightly lower carbs but keep protein at ~1.6-2g/kg to finish repairing
Common mistakeCutting carbs hard just because there is no run
Race week
Nutrition focusFamiliar foods, carbs near 6-8g/kg in the final 2-3 days, low-residue choices
Common mistakeChanging everything because nerves are high
| Training day | Nutrition focus | Common mistake |
|---|---|---|
| Easy run (under 60 min) | Normal meals; no gels needed. A light snack only if running early or fasted | Forcing gels or skipping food to manufacture a deficit |
| Tempo or intervals | 30-60g carbs in the 1-2 hours before; 20-30g protein plus carbs within an hour after | Trying to hit threshold pace on an empty tank |
| Long run (75+ min) | Rehearse race breakfast, then 30-60g carbs per hour and 400-800ml fluid per hour | Waiting until race week to test fuel and fluids |
| Rest day | Slightly lower carbs but keep protein at ~1.6-2g/kg to finish repairing | Cutting carbs hard just because there is no run |
| Race week | Familiar foods, carbs near 6-8g/kg in the final 2-3 days, low-residue choices | Changing everything because nerves are high |
A simple half-marathon training week
- Before easy runs: eat normally. If you run before breakfast and feel flat, a banana or a slice of toast with honey (roughly 20-30g of carbs) is plenty.
- Before workouts: take in 30-60g of carbs in the one to two hours beforehand — oatmeal, a bagel, or a rice bowl — so pace work tests your legs, not your blood sugar.
- During long runs past 75-90 minutes: practice 30-60g of carbs per hour and 400-800ml of fluid per hour, using the exact gels or drink mix you plan to race on.
- After hard or long sessions: aim for 1-1.2g of carbs per kg of bodyweight plus 20-30g of protein within the hour, and add sodium if you finished visibly salt-crusted.
- During race week: stop experimenting. Repeat the breakfast, caffeine dose, gel timing, and drink choices you already rehearsed, and lean toward lower-fiber foods to settle the gut.
Why a static calorie target falls short
The deeper issue with most nutrition apps is that they hand you one calorie and macro target for every day of the week. That number cannot tell whether tomorrow is a rest day or a long run, whether today turned out hotter than forecast, whether your workout slid from 6am to lunch, or whether your "easy" long run quietly included three miles at race pace. So it gives the same advice on a 3-mile jog and a 14-mile effort — and one of those days you are badly over- or under-fueled.
What actually moves the needle is matching intake to the demand in front of you: the duration and intensity of the session, when it falls in the day, how much recovery you need before the next one, and how hot it is. You can absolutely do this by hand once you know the gram targets above — a notebook and an honest read of your training plan will get most runners 80% of the way there. Tools that read your training calendar (Mavr is built around exactly this) automate the bookkeeping, but the principles below work regardless of whether an app or a spreadsheet does the math.
Frequently asked questions
Do I need gels during half-marathon training?
Not for every run. Gels or sports drink make sense during longer runs, race rehearsals, or sessions where you are practicing race-day fueling. Short easy runs usually need less.
Should I eat more on half-marathon workout days?
Usually yes. Tempo, threshold, interval, and long-run days need more carbohydrate availability than easy or rest days, especially if you want to hit pace and recover well.
Can I lose weight while training for a half marathon?
Sometimes, but aggressive restriction often hurts workout quality and recovery. Keep hard sessions fueled and use only modest adjustments on lower-load days if body composition is a goal.
How is Mavr different from a calorie tracker for half-marathon training?
Mavr starts with the workout calendar and actual training context, then adjusts meals, carbs, recovery, hydration, and timing around the sessions that matter.
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.
