Nutrition and Hydration

Nutrition and hydration are critical to getting the most out of your training and performing at your best in a race. It is also a crucial element in ensuring that you recover fully and in a timely manner between training sessions. The following are some thoughts on how to ensure you remain fuelled and watered to get the most out of your training and racing.

Nutrition

You should aim to consume a high carbohydrate, low GI (slowly absorbed carbs) meal 2-4 hours prior to training or racing. The meal should contain 2.5g/kg body weight of carbs and be moderate in fibre – e.g. baked potatoes, whole wheat pasta with low fat sauces. You could also take a lighter snack 1-2 hours prior to the exercise, examples would be bananas, cereal, rice pudding, sports bars. 

Where the exercise is expected to last longer than 60 minutes, you will need to replenish your glycogen stores and top up fluid levels during the exercise. Accessing an isotonic sports drink would be appropriate as they contain high GI (quickly absorbed) carbs as well as electrolytes to help fluid replenishment and some also contain protein. You should aim to replenish carbs at the rate of 1g/kg body weight/hour. Sports drinks, gels energy bars are all appropriate approaches to refuelling. A simple, homemade sports drink could be made by mixing 50% water with 50% fruit juice and a pinch of salt.

In the first 2hrs post exercise, when muscles are most receptive to replenishing lost energy stores, you should consume 1g/kg body weight of high GI carbs – e.g. fresh fruit smoothie, malt loaf and a further 50g of carbs in the 2-4 hrs after that. Post exercise you should also look to take on 15-25g of protein – a fresh fruit smoothie is an excellent post race choice as it combines carb and protein intake.

As a general guide for a good balanced diet, carbohydrate should account for between 50% and 55% of calorific intake, fat should account for 30%-35% and protein should account for 10%-15% of calorific intake. Vitamin and mineral requirements should be met by eating a varied diet, including fresh fruit and vegetables, but it may be necessary to use supplements in some circumstances. Where possible the diet should consist of fresh, non-processed foods.

Hydration

4 hrs prior to training or racing you should consume 5-7ml/kg body weight of fluid to ensure you start well hydrated. 

You should aim to drink at regular intervals during exercise as the stomach processes fluids more efficiently when kept topped up as opposed to emptying and then re-filling – drinking little and often is the key. Don’t wait until you feel thirsty before you drink as this is not always a good indicator of dehydration and be aware of the need to rehydrate in colder weather conditions as well as warmer ones.

Post exercise look to replace lost fluids by 150%. As guidance – for every 1kg in weight lost during exercise you will have lost 1ltr of fluid and should therefore replenish with 1.5 ltr. 

To calculate your rate of fluid replenishment more accurately you could weigh yourself without clothes before and after a one hour training session. Exercise at the intensity you plan to race at in your key race. Every kg lost is equal to a litre of fluid lost. For example if you are 0.75 kg lighter after training your fluid replenishment rate will be 0.75 ltr (750ml) per hour. You should aim to make up any deficit in body weight by 150% – in this scenario it would mean consuming 750ml x 150% – 1.125 ltr of water. Remember to account for any fluids consumed (or passed!) during the session as these will impact the result.Generally, you should aim to drink daily 1ml per kcal burned – e.g. if you burn 2800kcal per day you should be looking to consume 2.8ltr fluid per day.