Fuelling for Female Ultra Runners
Trail Notes | Training Nutrition
a practical reference for women
Fuelling for Female
Ultra Runners.
This is a practical reference for female ultra runners. It covers daily intake, long-run fuelling, race nutrition, common mistakes and the female-specific factors that change how we should think about training nutrition. It is written to be used, not just read.
The numbers below are guidance ranges drawn from current sports nutrition consensus for endurance athletes. They are starting points, not prescriptions. Your individual needs depend on body size, training load, life stage, gut tolerance and history.
If you have a history of disordered eating, low energy availability, REDs, GI disease or any medical condition that influences nutrition, work with a sports dietitian. This article does not replace individualised care.
The short version
Eat enough daily, match carbohydrate to training and rehearse a sustainable race strategy. General ranges guide testing; neither 60 g/hour nor a 40 g/hour floor applies universally. Higher intake may help some athletes, but 90 g/hour is not compulsory. Plan recovery food without a rigid deadline.
Section 01
Daily fuelling: getting the base right
Many fuelling problems in female ultra runners do not start in a race. They start in everyday under-eating. Your daily intake is the foundation. If the base is low, no race-day strategy will fix it.
A workable starting framework for a training female ultra runner:
Daily intake guidance
Carbohydrate
5 to 8 g per kg bodyweight on training days. Up to 8 to 10 g per kg on high-volume or back-to-back long-run days.
Protein
1.6 to 2.2 g per kg bodyweight, spread across 4 to 5 meals or snacks of roughly 25 to 40 g.
Fat
Include sufficient fat and essential fatty acids. The amount depends on total intake, training and health; 1 g/kg is not a universal minimum.
Energy availability
Low energy availability can affect health and performance. Historical figures of 30 and 45 kcal/kg fat-free mass/day are not universal diagnostic or safety cut-offs. Seek individual assessment rather than diagnosing REDs from a calculator.
Iron and ferritin
Discuss testing frequency with your clinician based on symptoms, bleeding, training and history. Do not supplement from fatigue alone.
Hydration baseline
30 to 40 ml per kg bodyweight daily, plus replacement for sweat losses in training.
Ranges adapted from current IOC and sports nutrition consensus guidance for endurance athletes. Adjust to individual context.
Section 02
Carbohydrate periodisation by session
Not every session needs the same fuelling. Match carbohydrate to the demand of the work.
Base Run, under 60 min
Eat normally before and after. Water during is usually enough.
Moderate run, 60 to 90 min
Consider a familiar pre-run snack, particularly before harder work or after a long gap without food. During 60 to 90 minutes, needs depend on intensity, prior intake and session purpose.
Long run, 2 to 4 h
General endurance guidance often uses 30 to 60 g carbohydrate/hour, with 60 to 90 g/hour useful for some prolonged demanding efforts. These are reference ranges, not a compulsory progression. Duration alone does not determine the hourly target. Use Her Gut Protocol to establish consistent intake, test useful changes and repeatedly rehearse your usual target with familiar fallback options. Around 40 to 50 g/hour progressing towards about 60 where appropriate is our UTA100 long-session coaching starting point, not a universal minimum or optimum. An established effective higher intake need not be reduced; 90 g/hour is not an expectation.
Long run, 4 h+
Use suitable scheduled long runs to rehearse usual intake, fluid, product portions and fallback foods. Practise maintaining intake late in the run; longer duration does not automatically require a higher hourly target.
Strength session
Support strength sessions with sufficient daily food and protein. Food around the session can help; eating within an hour afterwards is a practical habit, not a universal deadline.
Recovery day
Maintain protein and overall energy. Carbs can be slightly lower but should not drop dramatically.
Section 03
In-run fuelling targets
Carbohydrate intake during running is one of the most reliable performance levers. Many female ultra runners under-fuel during long efforts. Build this skill gradually. Do not jump to 90 g per hour without training the gut to handle it.
Carbs per hour during running
Under 60 min
0 to 30 g per hour, optional. Mouth rinse only is fine for shorter efforts.
60 to 120 min
For sustained moderate or hard work, 30 to 60 g/hour is a common guide. Shorter easier sessions may need less; prior meals and individual needs matter.
2 to 3 h
Around 30 to 60 g/hour is common guidance for sustained endurance work. Select a useful practised amount; 60 g/hour is not a compulsory standard.
3 h+
Some prolonged demanding sessions benefit from 60 to 90 g/hour using multiple carbohydrate sources. Test individually; passing three hours does not automatically prescribe that dose.
Ultra (50 km+)
For ultras, use the individual approach described above and in Her Gut Protocol. Rehearse a usual target and familiar fallback options, including later-race appetite changes. Duration alone does not prescribe a higher hourly amount.
Spread intake across the hour rather than taking a large amount at once. Many athletes tolerate small servings every 15 to 20 minutes better than one large hit per hour.
Section 04
Hydration and sodium
Hydration needs vary enormously. Do not copy what a male teammate is drinking. Test your sweat rate by weighing before and after a 1 hour run in similar conditions to your race.
Fluid during running
400 to 800 ml per hour as a typical range. Adjust up in heat. Do not drink to a fixed plan if you are not thirsty and not sweating.
Sodium during running
Use thirst as a starting guide and individualise sodium with food, drink, sweat losses and conditions. No single hourly dose fits everyone; sodium does not prevent harm from excessive drinking.
Sweat rate test
For a short representative session, sweat rate (L/hour) is approximately [pre-run mass (kg) minus post-run mass (kg), plus fluid consumed (L), minus urine passed (L)] divided by hours. Use comparable dry clothing. Long-ultra mass changes do not measure sweat loss alone.
Hyponatremia risk
Has been reported more often in women, especially in long ultras. Caused by drinking more fluid than you lose; sodium intake does not prevent it, so drink to thirst rather than to a schedule. Symptoms include nausea, headache, swelling, confusion. If symptoms are severe, stop and seek medical help.
Weight gain during prolonged exercise can indicate over-drinking, but does not diagnose the cause alone. Do not automatically treat suspected hyponatraemia by adding salt. Stop and seek event medical help for confusion, vomiting, worsening headache or marked swelling.
Section 05
Pre-run and pre-race fuelling
Pre-race intake matters more than most runners realise. Race-morning nerves often push women to eat less than they need. That is a common reason for an early bonk.
Race-morning timing
3 to 4 h before
Main meal: 1 to 3 g carb per kg. Familiar foods, low fibre, low fat, moderate protein. Examples: oats with banana and honey, white toast with jam, rice with eggs.
60 to 90 min before
Top-up snack: 30 to 60 g carbs. Banana, sports drink, small portion of toast or a sports bar.
15 to 30 min before
Final top-up: a gel or 200 to 300 ml of sports drink if it sits well in training.
Race start fluid
5 to 7 ml per kg, 2 to 4 hours before. Sip, do not gulp.
Caffeine
3 to 6 mg per kg, 30 to 60 min before, only if practised in training. Do not introduce caffeine on race day.
Avoid new foods, high-fat dishes, high-fibre meals or large portions you have not tested. The race-week kitchen is not the time for experiments.
Section 06
During the ultra: a usable race plan
Build a written hourly plan and rehearse it. Use a vest pocket card, a watch screen reminder, or a crew sheet. Do not rely on memory under fatigue.
Hourly race-day template (50 to 100 km)
Hour 1 to 2
Start regular familiar fuel early, using your rehearsed target and formats. Drink according to thirst and conditions. Do not wait for a marked energy drop.
Hour 3 to 5
Continue your rehearsed strategy, using tested sweet or savoury alternatives when useful. Count carbohydrate in actual portions, including drinks.
Hour 5 to 8
Review energy, appetite, conditions and actual intake. Use familiar alternatives to maintain fuelling. Soup and broth may contain little carbohydrate.
Hour 8+
Maintain useful intake through smaller portions and familiar formats. A temporary fallback is not a guaranteed safe minimum. Do not force food through worsening symptoms or repay missed intake with a large bolus.
For mild discomfort, ease effort and reassess heat, portion size and drink concentration. Try a familiar alternative in small amounts. Repeated vomiting, inability to retain fluids, severe pain, blood, confusion or collapse require event medical help.
Section 07
Recovery fuelling
Recovery starts the moment you stop running. Do not wait until you feel hungry to eat.
Soon after training, especially when recovery time is short
For rapid recovery between demanding sessions, carbohydrate and protein soon afterwards can help. With more recovery time, sufficient food across the day matters more than an exact deadline. Examples include yoghurt and cereal, a sandwich or a familiar recovery drink with food.
Within 2 to 3 h
A balanced meal with carbs, protein, vegetables and some fat. Eat enough that you do not feel like grazing all evening.
Fluid replacement
125 to 150 percent of weight lost, spread over 4 to 6 hours. Include sodium and food, not water alone.
Bedtime
After very long sessions, a 20 to 40 g protein snack before sleep supports overnight muscle repair.
Day after
Keep eating well. One good meal does not finish recovery from a long ultra. Full glycogen restoration can take 24 to 48 hours.
Section 08
Female-specific considerations
Life stage can change nutrition demand. Pregnancy, postpartum and perimenopause can all shift the picture. Some women notice patterns across the month, and some do not. Track your own: we train the person, not the phase.
Heavy periods
Heavy bleeding can increase iron-loss risk. Include iron-rich foods and discuss symptoms and testing frequency with your clinician.
Perimenopause
Sufficient protein spread across the day supports muscle alongside strength. Sports-nutrition ranges such as 1.6 to 2.2 g/kg/day guide individual discussion; precise menopause-specific requirements remain uncertain. Match carbohydrate to training.
REDs / low energy availability
Warning signs: missing periods, recurrent injury, poor sleep, low mood, persistent fatigue, frequent illness. Seek qualified support.
Fasted training
We encourage fuelling demanding sessions. Evidence does not support a blanket claim that every short easy fasted run harms women; consider total intake, comfort, training demands and recovery.
Be cautious with trends that advocate routine fasting, very low carbohydrate intake or aggressive restriction. The evidence base supporting these approaches in female endurance athletes is weak. The evidence supporting their harms is growing.
Section 09
Gut training
Gut practice can improve tolerance, but difficulty reaching a particular intake is not proof of inadequate training. Symptoms have several causes. Build an effective sustainable plan, with individual assessment for recurring problems.
A simple progression
Find your starting point
Find: record usual intake, energy and symptoms. Select an achievable starting plan; address inadequate fuelling with support. These stages do not require fixed weeks.
Build consistency
Train: repeat regular portions and a workable delivery system. Adjust one main variable where practical, without compulsory weekly increases.
Test useful changes
Test: assess useful changes in quantity, format and timing, including later-run preferences and practical food access.
Repeat and review
Prove: repeatedly rehearse your usual target and fallback options in relevant scheduled sessions. Do not add long runs to complete a nutrition task. No rehearsal guarantees whole-race tolerance.
If GI distress is consistent, look at fibre intake in the 24 hours pre-run, fat content of pre-run meals, hydration concentration, and running pace at the time of fuelling. These four factors are common culprits in race-day gut problems.
Section 10
Common mistakes
What to watch for
Under-eating daily
Long-term restriction undermines adaptation, recovery, hormones and immunity.
Skipping breakfast pre-long
Sets the run up to fall apart in the second half.
Too much fibre on race week
Reduce intake from 2 days out. This is not the week for kale and lentils at every meal.
New products on race day
Aid stations and goodie bags are full of items you have never trained with. Carry your own.
Drinking only water
Hyponatremia in long ultras comes from drinking more than you lose, not from a lack of sodium. Drink to thirst and add sodium to taste.
Late-race deficit chasing
Establish regular intake early. Do not try to repay missed fuel with a large late-race bolus.
Trusting wearables alone
Calorie estimates from watches are unreliable. Use them as rough trend data, not exact figures.
Section 11
Worked examples
To illustrate how the numbers play out, here are two example athletes. These are templates, not prescriptions. Adapt to your context.
Example 1 · 60 kg athlete, 50 km race
Daily training: 300 to 480 g carbs, 95 to 130 g protein, 60 to 80 g fat.
Pre-race breakfast (3 h out): 90 g carbs, e.g. oats with banana, honey and a coffee.
Pre-race top-up (45 min out): 30 g carbs, e.g. a gel and small sips of sports drink.
In-race fuelling:Illustration only: for an individual 60 g/hour target, a gel labelled 25 g, a drink portion containing 20 g and a food portion containing 15 g total 60 g. Check actual labels; product counts and flask sizes alone cannot establish intake.
Sodium:individualised to food, drink, sweat losses and conditions. No single dose fits everyone; sodium does not make over-drinking safe.
Example 2 · 65 kg athlete, 100 km race
Daily training (peak weeks): 450 to 600 g carbs, 110 to 140 g protein, 70 to 90 g fat.
Pre-race breakfast (3 to 4 h out): 100 to 130 g carbs, e.g. rice with eggs and toast with jam.
In-race fuelling:Use an individually rehearsed target rather than assigning intake from body mass or distance alone. Maintain it through tested products and foods, with alternatives for changing appetite. A universal 40 g floor or 90 g goal does not apply.
Fluid: 500 to 700 ml per hour, adjusted to temperature and sweat rate.
Sodium:individualised to food, drink, sweat losses and conditions. No single dose fits everyone; sodium does not make over-drinking safe.
Section 12
When to get help
There are situations where self-managed fuelling is not appropriate. Work with a sports dietitian or qualified clinician if any of the following apply.
You have missed 3 or more consecutive periods.
You have a history of disordered eating, restriction or compulsive exercise.
You are experiencing recurrent stress fractures or chronic injuries.
You feel persistently fatigued, low or unable to recover from sessions.
You are pregnant, postpartum or breastfeeding.
You have a diagnosed GI condition or food allergies.
You are entering perimenopause and noticing significant shifts in recovery or sleep.
Asking for support is not a weakness. It is good practice. The athletes who fuel best across the long term often have a qualified person checking their work.
Section 13
Final checklist
Daily intake supports training, health and recovery, with adjustments to individual needs rather than compulsory bodyweight ranges.
You plan food before long runs and afterwards, with timing reflecting the session and time before the next one.
Long-run fuelling matches race-day targets and gut tolerance is trained.
You have a written hourly race plan with carbs, sodium and fluid targets.
You know your sweat rate and have tested your sodium needs.
Iron testing frequency has been discussed with your clinician where relevant to symptoms and risk.
Any restrictive approach has been considered in the context of energy needs, recovery and health, with qualified support where relevant.
A note on personal plans
If you want a plan built for you
The numbers in this guide are starting ranges. They are not a replacement for an individualised plan. If you want fuelling that is tailored to your physiology, your training load, your race demands and your gut, we recommend working with an accredited sports dietitian.
Her Trails recommends Tamara Madden of Madden Nutrition. Tamara works with female endurance athletes, understands the demands of trail and ultra racing, and builds practical, evidence-based plans that adapt to where you are in life and training.
Recommended Sports Dietitian
Tamara Madden
Madden Nutrition · Personalised fuelling for female endurance athletes
Visit Madden Nutrition →Keep going with us
Further reading and evidence
Reviewed 2 November 2026 alongside Her Gut Protocol. Intake ranges are guidance, and research in female ultra athletes remains limited. A short successful rehearsal cannot guarantee whole-race tolerance.
