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Health Tips
Eating and Drinking Before Sport - Why should I eat and drink before sport?
by Gayl Sue
To perform well your body needs to have adequate carbohydrate fuel stores in the muscles and liver. Carbohydrate is stored in the muscles as glycogen to provide an important source of fuel for sport. If you are training or competing each day,particularly more than one session each day, it is crucial that you constantly restore your muscle glycogen levels. The carbohydrate foods eaten in the last hours before sport can help top-up this important fuel. Carbohydrate is also stored in smaller amounts in the liver (liver glycogen). This glycogen reserve helps maintain normal blood glucose levels, and becomes very important during prolonged workouts or endurance sport.
Your normal overnight fast will lower liver glycogen stores, which in turn can reduce your endurance. Eating a carbohydrate-rich meal or snack before sport gives you a much better chance of maintaining normal blood glucose levels and enhancing both physical and mental performance. And the pure enjoyment of eating your favourite pre-sport meal is a great confidence booster!
Dehydration in sport can ruin both your pleasure and your performance (Fact Sheet 1). In most situations, sweat loss during exercise is much greater than the amount of fluid an athlete can replace during a session. It makes good sense to start the session well-hydrated to minimise the fluid deficit that will inevitably occur.
This means drinking plenty of fluid with your pre-event meal or snack, and having another drink 10 - 15 minutes before the start of your workout.
What should I eat before sport?
As a guide, your choice of meal or snack should be:
- easy to digest,
- high in carbohydrate,
- low in fat,
- include plenty of fluids, and
- food and drinks you enjoy.
See the tips on this page for pre-sport meal ideas. High carbohydrate foods are great in topping up liver and muscle glycogen stores. Choose your menu to comfortably meet your needs, based on foods you know won’t cause any stomach upsets. Experimenting with your competition plan during training is highly recommended. It is unwise to try new foods or drinks on the day of an important event. Athletes who easily get stomach upsets or have sensitive intestines, and find it difficult to eat solid food before competition, should try choosing low fibre carbohydrate foods or ‘liquid meals’. A reduced fibre intake can help prevent bloating, diarrhoea and stomach discomfort. Liquid meals, such as commercial high carbohydrate drink supplements and home-made fruit smoothies, allow an athlete to fuel up without that ‘full’ feeling.
Smart Pre-exercise Eating Ideas
- Breakfast cereal with reduced-fat milk and fruit
- Porridge with reduced-fat milk and fruit juice
- Muffins or crumpets with honey/jam/syrup
- Toast with honey/jam/syrup/Vegemite
- Baked beans on toast
- Creamed rice (with reduced-fat milk) and tinned fruit
- Spaghetti with low-fat tomato based sauce
- Jacket potato with creamed corn
- Low-fat breakfast bar or muesli bar, and a banana
- Roll or sandwich with banana and honey
- Fresh fruit salad with low-fat yogurt or low-fat dairy dessert
- Smoothie, based on reduced-fat milk, low-fat yogurt and banana/mango/berries
- Soy smoothie, based on reduced-fat soy beverage and blended fruit
Can I Eat Sugar Before Exercise?
Many athletes are concerned whether eating sugar or sugary foods/drinks in the hour before exercise will affect their performance. They have heard that carbohydrates (sugar is a carbohydrate) may adversely affect blood glucose and insulin levels. When insulin levels are raised just before exercise, there is potential for a rebound drop in blood glucose levels (hypoglycaemia) and an increased use of carbohydrate stores during exercise. This may not be good for an athlete’s performance and endurance. However, recent research indicates that in most people, the drop in blood glucose that follows carbohydrate intake before exercise is short lived. In most cases, metabolic alterations are corrected within 15-20 minutes of exercise, and furthermore, the athlete may actually benefit from glycogen boost provided by the extra carbohydrate. Nevertheless, it appears that a small group of athletes suffer a pronounced reaction to carbohydrate intake in the hour prior to exercise. Such individuals should experiment with food intake before training to find a plan that works for them. In some cases, it might be necessary to avoid carbohydrate in the hour before exercise. In other cases, a switch to low GI carbohydrate choices might minimise any unwanted side-effects.
When Should I Eat and Drink Before Exercise?
It’s recommended that the pre-event meal is consumed 2-4 hours before competition. Your decision will vary according to the type and timing of the event. You will need to allow enough time for the meal to be emptied from the stomach. Low-fat, high carbohydrate meals and snacks empty the quickest from the stomach. Anxiety can slow stomach emptying. If you get nervous before sport you should allow more time for your stomach to empty. It’s important that the timing is right for gastric comfort - neither leaving you too full at the start of the event, nor hungry late in the session. For events in the morning, an athlete might schedule their breakfast 2-3 hours prior. In the case of a very early start, most athletes prefer to have a lighter snack 1-2 hours before the event and a larger supper the night before. Those competing later in the day may choose to eat their normal meals in the earlier part of the day and then have a light snack 1-2 hours prior to the event.
Carbohydrate Loading
In endurance events (events longer than 90 minutes) and ultra endurance events (events longer than three hours) the body's usual stores of carbohydrate are not enough to sustain the exercise. To overcome this problem a technique known as carbohydrate loading is used. This can result in an increase in glycogen stores by as much as 200-300%. Carbohydrate loading before the event involves six days of gradual tapering of training, with the last three days including a very high carbohydrate intake (7- 10 grams of carbohydrate per kilogram of body weight). To make sure you are well-hydrated, it is important to increase fluid intake at this time also. Many athletes will find that they need to use sugar and other compact carbohydrates to meet carbohydrate needs without excessive bulk. Endurance athletes who will benefit from carbohydrate loading should consult their sports dietitian for individual advice.
Summary Points
- Choose high carbohydrate, low fat foods with which you are familiar and comfortable.
- Experiment with the timing and type of meals to suit your personal preferences and your sport.
- Practice different eating ideas in training, not during competition.
- Develop a good pre exercise drinking strategy to minimise dehydration.
- Try a liquid or low fibre meal if you suffer from pre-competition nerves.
- Monitor the effects of your food and drink choices on your performance.
- Speak to a sports dietitian about carbohydrate loading before endurance and ultra-endurance events.
- Contact Sports Dietitians Australia for other sports nutrition resources.