Men's health

Sports nutrition for triathletes

Ideally, experienced athletes will have started preparing months before their major event with an improvement in their baseline nutrition for body maintenance.

Key nutrients to consider

They may then practice incremental increases in carbohydrate and fluid intakes before, during and after training to simulate the demands of competition.


During competition the body prefers to breakdown glycogen (carbohydrate stored in the liver and muscles) into glucose. If these stores are not replaced regularly then the fuel line becomes depleted, fatigue sets in and it becomes impossible to maintain exercise intensity and make decisions. Also the body begins to breakdown healthy tissue for energy. For this reason 60-70% of the energy for the race should come from carbohydrate foods such as breads, rice, cereals, pasta and fruit.


This is also important to preserve muscle growth and repair, immunity and to sustain energy levels. Therefore around 12-15% of total energy should come from protein. Best food sources include meat, cheese, eggs and low-fat dairy products.

While some athletes may manage protein during the race in the form of a ham or cheese roll, others may prefer it in the form of yoghurt at the start, 1-2 protein bars throughout the day and some creamy rice followed by a low-fat evening meal after the race.


As fat slows digestion rates it should be kept to low levels during competition around 20-25% of total energy intake.


This should be avoided in the build up to race day as it impairs co-ordination, strength and judgement for up to 48 hours after use.


In events up to ~20km the individual should have all fuel needs on board, those involved in longer events should endeavour to meet carbohydrate needs of 1g/kg/hour. Fluid needs should also be considered, especially as distances and/or temperatures increase. Athletes should determine needs according to sweat losses and replace these losses throughout the event rather than leaving it until the finish line.

Plan to succeed

Some races ensure refuelling stations are provided en-route, however this is not always the case and the well prepared athlete may have to carry snacks of fruit, muesli bars or gels in a bum bag and a camel pack of water to ensure continued hydration and energy during the race. Support teams can also make all the difference during transitions, by restocking these snack and fluid supplies.

Best of luck!

For further information on sports nutrition, or for individualised advice contact us today.

About the author View all

Lea Stening

Lea is one of New Zealand’s leading paediatric dietitians and also specialises in Sports Nutrition. She has specialised in Paediatric Nutrition for 31 years and in 1985 was the first paediatric dietitian to enter private practice in New Zealand. Lea helps families through her private consultations, public lectures, newspaper and magazine articles as well as television and radio interviews. Read more »

View all posts by Lea Stening »


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