Nutrition for Endurance Races

Triathlons – or any race lasting over 1.5 hours – calls for an effective nutrition plan. Without this you may find yourself unable to complete the event or taking longer than necessary to recover.

 Your nutrition plan should cover three areas:

  • Pre-Race: Sufficient hydration and glycogen loading

  • During Race: Hydration, calories and electrolytes to keep going

  • Post-Race: Refuel with carbohydrates and protein to ensure recovery process

In this post, I’ll share some observations and personal experiences in each of these areas. Pre-Race

  • Start the race well hydrated

  • Ensure that you consume lots of fluids in the days before the race

  • You should not try to drink a lot the morning of the race to overcome pre-race deficiencies

  • Build up your fuel reserves in the days before the race

    • When going over 90 minutes muscle and liver glycogen is the primary fuel source

    • Glycogen stores get depleted as the event progresses

    • Your system can only store enough glycogens for about 2 hours of racing

    • You need to ensure prior to the race that you are consuming enough carbohydrates to ensure that your glycogen is not depleted

    • Typical recommendations are for 6-8 grams of carbohydrate per kg of body weight per day—someone 150 lbs needs 410-544 per day; up to 680 g/day for heavy trainers

    • Need to ensure that your daily protein intake is about 10-15% of your total calories

  • On the day of the race take 1-4 grams of carbohydrate/kg 1-4 hours before the race

  • Some people use carbohydrate loading pre-race which allows you to store 2-3 times normal amount of glycogen in muscle. It works for races up to 2 hours in length.

    • Consume normal 60-75% carbohydrate diet for the training diet.

    • Exercise hard at 70-75% aerobic capacity for 90 min to deplete glycogen stores 1 week before event. (same exercise as event) Reduce carbohydrate intake to 4 grams per kg (50% of total calories)

    • Following initial depletion, reintroduce carbohydrate at about 70% total intake (8-10 grams/kg). Training is reduced in time by half to 40 min. on days 6 & 5 before the event. On days 4 & 3 before event, exercise is reduced by half again to 20 min.

    • Day before competition is rest day. Helps replenish glycogen stores.

 My experience: During training you should (1) drink lots of water; and (2) maintain a high carb diet, low in fibre and lactose (milk/sugar) and moderate in protein and fat. I don’t do carbohydrate loading; too difficult to get it right so it isn’t worth the bother. The day of the race eat sparingly. If you’ve done things properly, you don’t need a lot of fuel. The day of the race I use ‘Cytomax Pre-formance’ – 1 glass per 2 hours of race time. It has: 260 calories in a drink (35 g carbohydrate/26 g protein) along with electrolytes. Most importantly, it sits well in my stomach and as a drink also helps with hydration. During Race

  • The table below shows recommendations based on length of exercise


 From: Arnie Baker ‘Essentials for Sport nutrition’ ( 

Hydrate or die!

  • 8 oz/250 ml every 30-60 minutes depending on heat
  • Don’t drink too much either!
    • Can get hyponatraemic encephalopathy – a severe lack of salt in the blood – which can kill
    • Can be caused by drinking just water or sports drinks without sodium

Fuel or bonk!

  • Depending on body weight, need 25-30 g of carbohydrate (100-200 calories) for every 30 minutes during exercise
  • You body cannot synthesize more than about 300 cal/hour so do not consume too much


  • Minerals such as sodium, chloride and potassium
  • Electrolyte deficiencies can arise because of hyperhydration, dehydration and sweat
  • Body loses 1 gram of sodium per litre of sweat – about 2 g/h for many athletes; more if hot
  • Best to take electrolyte supplements to ensure no problems 

My experience: In most races lasting 2 hours or longer competitors don’t eat or drink enough. Plan to have about 300 cal/hour during the race, comprised of a combination of energy drink and gels or other foods. Set you watch to remind you every 20 minutes to have 100 calories, or do it by distance. For energy I use: (1) EFS sports drink for fluids; (2) Accel Gel for 100 calorie energy hits; (3) FRS orange antixidant health chews for smaller energy hits and variety; and (4) Cliff Mojo Bars for energy as well as more variety – you can chew them. Take ‘Endurolyte’ capsules every 3 hours to keep up your electrolyte balance. ‘Sport Legs’, which is a calcium supplement, may also help.Variety is important: if you are going several hours mix your foods. Whatever you plan on using, be sure to have tried them before the race. If possible be self sustaining: if you are relying on the race aid stations you may get something that your stomach may not like.


Immediately after heavy exercise muscle cells are more sensitive to insulin which promotes glycogen synthesis. Prompt refuelling will promote faster recovery.

  • At least 50 g of carbohydrate per hour (200 calories) within 30 minutes of exercise
  • Continue for up to 3 hours depending on caloric deficit
  • Protein with the carbohydrate will not go amiss
  • Cold, low fat, acidic foods are absorbed faster which helps with sore stomachs after the race (examples are cold oranges, juice or popsicles)
  • You should increase your protein intake for 3 days after the race – up to 10 days if it was particularly brutal

My experience: One of the best recovery drinks is chocolate milk. My ‘Horizon Organic’ 8 oz/238 mL bottle has 27 g of carbohydrates, 8 g of protein with 180 calories. These compare well with my second choice, Hammer ‘Recoverite’ which has 32 g of carbohydrate and 10 g of protein, along with lots of other extras. Chocolate milk is just a lot easier to get, and it tastes much better. I typically have a couple of chocolate milk and yoghurts for the first 6 hours or so after a hard race. By then my system has settled down so I can have more regular food.

Recommended Reading:

Arnie Baker ‘Essentials for Sport nutrition’ (

Lisa Dorfman’s ‘The Vegetarian Sports Nutrition Guide’ (


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