Ultramarathons place enormous physical, mental, and metabolic demands on the body. Most runners know that nutrition is important but struggle knowing what to do on race day. This article will cover
- Common mistakes
- Carbohydrate loading
- Pre-event meal
- Intake during the race
- Advice for different length ultras
- Hydration strategies
So let's get started learning more about ultra marathon race nutrition.
Common mistakes made on race day for an ultra-marathon.
- Not having a strategy and winging your food intake
- Trying new foods, drinks, or supplements on race day.
- Fuelling too late into the race
- Eating too much in one go
- Not being aware of fluid and electrolyte intake resutling in an imbalance
- Not having enough fuel on you for the race
- Not looking at where the aid stations are and what products they provide
- Eating the wrong foods (just carbs the entire time or too much fibre, fat and protein)
This article will address all of these.
One of the biggest factors that prevents optimal performance on race day is making your nutrition choices different to what you do in training. You must replicate some elements beforehand.
Removing decision stress around nutrition is CRUCIAL.
Use the time away from training to replicate the following -
- Your evening meal the night before the event
- Your breakfast on event day
- Any snacks you will consume on the event day
- Any nutrition products you will use (gels, pre-workouts, hydration etc)
Carb loading
This should be used for any ultra-marathon race. The reason I suggest reducing the amounts the day before slightly is to ease the digestive load. 3 days higher intake with reduced training you will adequate loaded glycogen stores.
Carb loading cheat sheet
|
Bodyweight (kg) |
Bodyweight (lb) |
5 g/kg (Low Rec) |
7 g/kg (Mid Rec) |
9 g/kg (High Rec) |
|
55 |
121 |
275g |
385g |
495g |
|
60 |
132 |
300g |
420g |
540g |
|
65 |
143 |
325g |
455g |
585g |
|
70 |
154 |
350g |
490g |
630g |
|
75 |
165 |
375g |
525g |
675g |
|
80 |
176 |
400g |
560g |
720g |
|
85 |
187 |
425g |
595g |
765g |
|
90 |
198 |
450g |
630g |
810g |
|
95 |
209 |
475g |
665g |
855g |
|
100 |
220 |
500g |
700g |
900g |
|
105 |
231 |
525g |
735g |
945g |
|
110 |
243 |
550g |
770g |
990g |
What to eat
This is not an excuse to go all in on the cookies. The quality of your food matters.
Tips to help you get to a higher carb intake.
- Increase meal frequency. Don’t just “eat big”
- Take advantage of liquid nutrition
- Stick to foods you are familiar with
Foods to build your carb load around...
Example for me weighing 72kg
- Carbs: 505g (7g/kg)
- Protein: 115g (1.6g/kg)
- Fat: 43g (0.6g/kg)
|
Meal |
Ingredients |
Calories (kcal) |
Carbs (g) |
Protein (g) |
Fats (g) |
|
Breakfast (7:00 AM) |
80g gluten-free oats (cooked with almond milk) - 1 medium banana - 1 tbsp honey - 1 tbsp peanut butter |
570 |
99 |
13 |
15 |
|
Snack (10 AM) |
4 rice cakes - 1 tbsp almond butter |
320 |
55 |
6 |
10 |
|
Lunch (1:00 PM) |
200g cooked white rice - 150g sweet potato - 120g chicken breast - 30g avocado - 1 tsp coconut oil (for cooking) |
720 |
108 |
40 |
13 |
|
Snack (3:30 PM) |
- 250ml pomegranate juice - 150g frozen berries - 200ml almond milk - 30g whey isolate protein |
400 |
59 |
27 |
4 |
|
Shake and snack |
Dried mango and apricots 30g whey protein shake |
320 |
44 |
27 |
1 |
|
Dinner (7:00 PM) |
250g cooked white rice - 120g grilled salmon - - 100g steamed broccoli |
670 |
80 |
34 |
15 |
|
Evening Snack (9:00 PM) |
150g Greek yoghurt - 3 tbsp honey - 3 medjool dates |
480 |
80 |
16 |
5 |
|
DAILY TOTAL |
3,480 |
505 |
116 |
43 |
Race day
Race day is all about energy availability yet most ultra runners fall short.
Data from 24-hour events shows runners burn ~13,140 kcal but only take in ~4,780 kcal.
One thing we can take from the research is that finishers consistently eat more.
A study of a 100 mile event showed elite runners averaged 333 kcal/h whilst non-finishers consumed <200 kcal/h.
The key metric to focus on was that finishers consumed 250–300 kcal/h.
This came from predominantly carbohydrates of around 71g/hr. The rest from small amounts of protein and fat.
Most runners don’t under fuel from laziness; it’s usually poor planning and lack of gut training.
Let's map out a race day strategy.
|
PRE RACE MEAL ADVICE |
|||
|
Protein |
Carbs |
Fats |
When to Eat |
|
0.5g/kg/bw |
1.5-2 g/kg bw |
0.25g/kg bw |
~3 hours before |
|
Ideas |
|||
|
Bagels with egg + egg white scramble, jam and pomegranate juice |
Overnight oats with fruit & honey. Slices of toast. |
Banana and oat pancakes with maple syrup, oranges and berries. Side of juice. |
Eggs on toast with bowl of cereal and milk and piece of fruit |
|
30-45 minutes pre race (aiming for 30-40g carbs) |
|||
|
2 x scoops MARCHON workout fuel with 1 scoop of electrolytes (750mg sodium) |
300ml fruit juice + soreen bar + electrolytes |
Rice krispie bar with gel + electrolytes |
Crackers with jam and thin spread of nut butter + electrolytes |
Fuelling strategy
Here is a table outlining a guide for intake during an ultra.
For ultras around 60-75g per hour is a good range to aim for. If you have done multiple ultras then bumping to 90g may be doable.
| Race Duration / Distance | Carbohydrate Target | Protein intake | Fat intake | Notes |
| 4-5 hours (e.g. 50k) | 60–90 g/hour | Not needed | Not needed | Gels, chews, liquid carbs are ideal here. |
| 5–8 hours (e.g. 50k–50 mile) | 60–90 g/hour | Optional (5–10g/hour) | Optional (small amounts) | Introduce bars and other carb based snacks. |
| 8–12 hours (e.g. trail 50 mile) | 70-90 g/hour | Optional (5–10g/hour) | Optional (small amounts) | Mix solid and liquid carbs; small fat adds satiety and variety. |
| 12–24 hours (e.g. 100k–100 mile) | 70-90 g/hour | Yes (5–10g/hour) | Yes (5-10g per hour) | Combine solids, liquids, and savoury foods for gut comfort and food variety. |
| 24+ hours (multi-day) | 70–90 g/hour (avg) | Yes (5–10g/hour) | Yes (exact amounts will vary) | Fat and protein support a consistent calorie intake. |
Tips for intake during the race
- For longer races, include savoury foods such as wraps, sandwiches, pretzels, crackers, and rice cakes. Sweet fatigue is a real thing, so try different options for longer races. This is one of the reasons we created an unflavoured energy gel.
- Use fat sparingly, mainly for palatability and satiety, not as a primary fuel. Longer races more fat is sensible. Fnishers of 100 mile races ate 5x more fat than non finishers.
- Use protein during ultra-endurance races of 6–8 hours to support muscle preservation.
- Practice gut training in advance to tolerate higher intakes.
- A mixture of liquid, solid, sweet and savoury is often what is reported to be the best approach.
As I have mentioned, maintaining a calorie intake of around 250-300kcal/hr, aiming for at least 60g of carbs per hour is what you should have in your plan.
Fuelling strategy - carbs
With most endurance events, athletes feel good at the start due to a large pre-race meal. But one tip I would give you is to start fuelling earlier than you think.
A study done on the race diet of finishers and non-finishers in a 100 mile (161 km) mountain footrace showed overall consumption rates of kilocalories, carbohydrate, fat, and sodium were significantly greater in finishers than non-finishers.
Here is an overview based on how many carbs you are aiming for. Practical issues of taking the amount of food is something to consider so know your route and the aid stations.
|
Target |
Feed Interval |
Carbs per Feed |
Example Intake Options |
|
60g/hour |
Every 30 min |
30g |
- 1 gel (30g) - 500ml carb drink - 1 banana + ½ bar |
|
75g/hour |
Every 30 min |
30–45g |
- 1 gel + sports drink - Half banana wrap + dates - Energy chew + sips drink |
|
Every 20 min |
25-30g |
- ½ flapjack - 3–4 dates - Sips of high-carb drink - gel |
|
|
90g/hour |
Every 30 min |
45g |
- 1 gel + carb drink - ½ jam sandwich - pretzels + dried apricots |
|
Every 20 min |
30g |
- 1 gel per feed - 1 banana + ½ chew - rice krispie squares |
Hydration
Providing accurate fluid and electrolyte advice is challenging due to the number of factors that affect sweat rate and composition, plus the practical challenge of carrying this.
Here is a simple baseline overview.
- Fluid volumes of 450–750 mL·h− 1 (~ 150–250 mL every 20 min) are recommended during racing. Research shows average fluid intake during a 24-hour race is ~378 mL·h, yet some athletes consumed up to 673 mL·h.
- To minimise the likelihood of hyponatraemia, electrolytes (mainly sodium) may be needed in concentrations greater than that provided by most commercial products (i.e., > 575 mg·L− 1 sodium).
- If you are a heavy sweater or it is humid conditions, then you may need to bump this up. Take electrolyte sachets to top up water at stations or salt tabs.
- Make sure to get up and get hydrated with at least 750ml of water and electrolytes first thing. Then sip on water and electrolytes leading into the race. Proactive hydration will help.
Next up in the series is Ultra-marathon supplementation and extras. This will cover
- Supplements to use in training
- Supplements for race day
- Post-race advice
