Hydration is as important as fuelling. It enables optimal performance. If you are dehydrated, this causes cardiovascular stress and fatigue. Drink 350–500ml of fluid 2-3hours before the run. During the run, drink 400–800ml fluid per hour. Drink little and often, but not excessively.
For speedy recovery, remember the 3 Rs: Rehydrate, Refuel and Rebuild. Refuelling is faster than normal during the first two hours so make use of this window. Timing is key, so include protein in all meals and snacks to distribute protein consumption throughout the day.
Last days leading up to the event
As your glycogen reserves do not have infinite capacity, and can fuel up to 1½-2 hours exercise, you will benefit from carbohydrate loading. This is a process of maximizing your glycogen stores in preparation for an endurance event and may improve endurance by 2-3%. During the final two days increase your intake of carbohydrates to 7-10 g/kg body weight per day. Carbohydrate loading must not be confused with eating as much as you can.
The day before
Continue to eat normally and avoid anything new. Drink plenty of water and eat several small high-carb meals to optimize glycogen storage. To avoid performance repercussions avoid high fibre, hard to digest and gas-forming foods, such as beans, pulses, sprouts and spicy foods. Avoid eating overly late in the evening and do not over-eat.
Before you set off
Aim to have breakfast 2–3 hours before the run. Include foods rich in carbs and protein. Porridge is the perfect pre-run breakfast and extra milk, fruit and nuts will deliver sustained energy. Two or three eggs with toast or a generous bowl of granola with milk, yogurt and fruit are also excellent nutrition options. About 30–45 minutes before the start, sip 125–250ml of water, squash or a sports drink. If you can, consume an extra 25g carbs, such as a banana, gel or a small nut bar.
Fueling during the race
Start fuelling after about 30–60 min and then plan to have 2–3 micro feeds (15–30g carb) every 20–30 min. The key is to eat little and often. Optimal nutrition snacks include isotonic sports drinks of 250 ml, a banana, 20g raisins, 20g apricots, 30ml energy gels, oat energy bars or homemade granola bars.
Some athletes use caffeine to deliver a boost towards the end of a race. Beet juice is packed with dietary nitrates, which foster blood vessel dilation and increase blood flow to muscles during exercise. Studies have shown that drinking beet juice prior to running may enhance performance.