Answer: After about 80 minutes of continuous exercise, your body’s stores of carbohydrate (i.e. fuel for your muscle and brain) are normally used up. You will have also lost water and electrolytes through sweat. This could make you dehydrated and upset your electrolytes balance which could have a negative effect on your performance. This is why a source of carbohydrate and electrolytes may be beneficial if you’re doing a high-intensity event or exercise session lasting longer than 60-90minutes. A 50Km run is the ideal event to use an additional source of carbs and electrolytes.

Gels are a good source of carbohydrate. They normally contain about 25g of carbs per gel and need to be taken with about 300mL of water. You need about 30-60g of carbs per hour, so this means about 2 gels per hour, along with water. However, some gels don’t contain electrolytes. This means they won’t help your electrolyte balance, or support hydration as well.

To combine carbohydrates and electrolytes to support hydration and fluid retention, try using a sports drink such as Balance Restore Energy Powder at regular intervals (e.g. 200mL every 20 minutes).

Like everything, practice makes perfect. Be sure you practise your fuelling and hydration strategies during training runs to make sure you are set for the day and are confident that your body responds well to the strategy and that it won’t cause problems! Remember: “nothing new on race day”.

Emily is the Nutritionist at Healtheries. For more information about Healtheries, one of New Zealand's most trusted health brands, visit www.healtheries.co.nz or phone 0800 848 254.