Nutrition – an insight into endurance

It is well recognised that:

  • What we eat and drink…..
  • When we eat and drink…..
  • How much we eat and drink…..

These can all influence sporting performance and the way we feel.

Eating for Sport:

  • Eat a wide variety of foods
  • Eat plenty of starchy foods at mealtimes
  • Eat moderate protein i.e. 60-75g
  • Include 5 portions of fruit and veg daily
  • Reduce saturated fat (butter) and increase omega 3 & 6 fats (fish oils)
  • Keep sugary foods to small quantities to support energy needs

‘Most people eat too much protein (100g) which causes acidity in the body’

Fuel for Sport

Muscles are powered by glycogen which is stored within them. In prolonged exercise you must consume carbohydrate to replace these stores to delay the time before the onset of fatigue. Fat stores can also be mobilised but it is much harder to convert to energy and will depend on the intensity of the exercise.
So, the bigger the glycogen stores, the further you can go.


  • 2.5 litres of fluid is needed daily to be well hydrated
  • Additional fluid is needed when exercising
  • Fatigue with dehydration usually occurs before depletion of glycogen stores
  • Drink water, squash, fruit juice (can be diluted)
  • Avoid diuretics like coffee, tea, cola & alcohol
  • Hydration can be checked by the colour of your urine. Aim for clear or pale yellow. Orange = dehydrated

‘A 2% dehydration causes a 3% dip in performance over 5k and therefore a 6% dip over 10k’

Glycaemic Index

The lower the GI the slower it will be released as energy into your body

  • Low GI Foods – pulses, beans, lentils, porridge oats, vegetables, milk, yoghurt
  • Moderate GI Foods – fruit and fruit juice, dried fruit, chocolate, bread, brown rice, cous cous
  • High GI Foods – foods containing sugar, sweets, jam, honey, jaffa cakes, bananas, pasta, potatoes, white rice

‘Low GI foods keep you feeling full for longer and so aid weight management’

Alcohol – the pros & cons


  • Contains carbohydrate for refueling post exercise (but also diuretic)
  • Not illegal in triathlon


  • Most calorie dense substance – even more so than fat!
  • Increases injury rate due to vasodilation
  • Reacts with lactic acid to cause muscle soreness
  • Makes you feel hungry as it is High GI

‘Alcohol hinders sports performance at levels lower than the legal driving limit’

Drinking Habits

  • Make the first drink of the day hot water with the juice of half a lemon squeezed in. This will wake the digestive system ready for food and hydrate
  • Make the last drink of the day hot water to hydrate during your sleep
  • Drink in between meal times but not at mealtimes as the fluid will dilute the digestive juices and hinder digestion.
  • Avoid caffeine (tea & coffee) after a meal as it limits the absorption of vitamins and minerals

‘ Aim to drink 2.5 litres of water a day but not 30 mins before or after a meal’

Points to Consider

  • Exercise produces free radicals in the body which are highly reactive and damage cells– increase intake of anti-oxidants to mop these up i.e. vitamin C & E
  • Eat nuts and seeds for Essential Fatty Acids which help build and repair cell membranes
  • Eat little and often to achieve a consistent level of glucose in the blood to maintain energy levels and minimise hunger pangs. Choose Low GI foods
  • If the body is in a state of dehydration it will not release fat from cells – so to lose weight you must be hydrated

‘If you eat more calories than you burn you will store it as fat’

Every person is an individual due to their unique genetic profile. Therefore, what works for one body may not work for another. Please consider this when trying any new supplement or nutritional programme.

‘Listen to your body – if you are not feeling any improvements then stop it and try something else!’