Nutrition During Exercise

Poor nutritional practices during endurance exercise could leave you dehydrated and fatigued. It is very important to pay special attention to what you eat and drink on race day as well as when training. Getting to know what your body can or can’t tolerate during training will help to prevent unexpected upsets on race day. Rehydration and refuelling make up the cornerstones of during-endurance nutrition, learn how to manage these here.


The loss of just 1% of body weight through sweat can lead to a reduction in strength, while 7-10% can could you to collapse. Though unlikely with moderate fluid intake in our climate – over-hydration also carries risks. For events lasting less than 60-90 minutes it may be alright to rely on thirst as an indicator that it is time to drink fluids. However, for endurance events it is a good idea to have a plan for your fluid intake and to stick to it. A general guideline to prevent dehydration and over-hydration is to drink 3ml of fluid per kg of body weight every 20 minutes. Practically this can be achieved with half to a whole cup of fluids every 15 minutes (roughly every 2 kilometres for the average runner) .

Rehydration during endurance events requires more than just water as electrolytes are also lost in sweat. It is very important to replace sodium as it prevents urinary fluid losses and is necessary for the transport of glucose to provide energy. Potassium assists with efficient rehydration and should thus also be made a priority.


Our bodies are only able to store limited amounts of carbohydrates in the form of glycogen. When levels get too low we begin to feel fatigued and light headed. We therefore need to refuel with high glycemic index carbs when participating in endurance events. Requirements are 30-60g of carbohydrates per hour, this may increase to 90g for events exceeding three hours. Your requirements will increase from the lower to the higher range depending on the time and intensity at which you participate. For a high intensity event try to have 15g of carbs at each 15 minute rehydrating interval.

Sports drinks can be very useful for fulfilling at least part of your fluid and carbohydrate requirements. The optimal sports drink would have a carbohydrate concentration of 7% or 7g per 100g. 725ml of a 7% concentration sports drink will provide you with 50g of carbohydrate which is sufficient to provide for one hour’s requirements under most circumstances. Any sports supplement with a carbohydrate concentration of above 10% may cause gastrointestinal discomfort or disturbances and should be washed down with water to lower the concentration.

FUTURELIFE® High Energy SmartBars provide you with +/- 25g of carbohydrate per bar, contains electrolytes and provides you with high GI, fast release energy making it an ideal snack for during exercise.