‘How to Maximise Your Exercise Performance with Food’
Following a healthy diet that contains adequate amounts of energy, carbohydrates, protein, vitamins and minerals is absolutely vital for optimal exercise performance. What and how much you eat around your exercise schedule can make a big difference to how you feel and also to your stamina, strength and power. Eating too much or too little, or eating at the wrong time can affect your performance and leave your feeling hungry, uncomfortable or unwell.
Pre-Exercise Nutrition
Ideally, you should be eating your pre-exercise meal 2-4 hours before you plan to workout because its early enough to digest the food, yet late enough that the energy won’t be used up by the time you start exercising. Eating a meal too close to training could make you feel uncomfortable and nauseous as the blood supply diverts from the stomach and digestive organs to the muscles to provide the necessary energy for the exercise. The body is not designed to digest a big meal and exercise at the same time!
On the other hand, leaving too long a gap might leave you feeling hungry and light-headed during exercise, and lacking energy. The closer your pre-workout meal is to your workout, the smaller it should be. If you don’t have time for a full meal, then a small snack like a banana or a smoothie 30-60 minutes before hand will do the trick.
The bottom line is, you should feel comfortable before your workout, neither hungry or full.
Hydration
Its crucial that you are fully hydrated before you begin exercising, otherwise you risk dehydration early on in the session. This can affect your stamina, speed and performance and can cause early fatigue, headaches, nausea and dizziness.
Prevention is better than cure. If you’re exercising in the evening, make sure that you drink plenty of water during the day. If you’re exercising early in the morning, have a drink as soon as you wake up. The easiest way of telling how hydrated we are is through the colour and smell of our wee – it should be a pale yellow and shouldn’t have a strong odour.
For workouts lasting less than an hour, then water is the best choice. It is absorbed rapidly and hydrates the body. For longer sessions, consuming extra carbohydrates in the form of a drink (e.g., squash or a specialist sports drink) will also help to maintain blood glucose levels and fuel the muscles.
Current advice is to drink when you are thirsty and to listen to your body. For most workouts, 400-800ml of fluid per hour will prevent dehydration (as well as over hydration). You should aim to consume fluids at a rate that reflects your sweat rate – you’ll sweat more in hot and humid conditions and when you are working harder.
After exercise, replacing lost fluids should be a priority as your muscles can’t fully recover until your cells are properly hydrated. Replacing lost fluid takes time and is best achieved by drinking little and often. Drinking a lot in one go will only stimulate urine formation, so most of the fluid will be lost rather than retained.
Nutrition During Exercise
For endurance workouts lasting longer than an hour, consuming extra carbohydrates can help you to maintain your pace and to keep going for longer. You should aim to consume between 30 and 60 grams per hour.
If you’re exercising for longer than 2 ½ hours (e.g., ultra-running, triathlon, cycling, or marathon) then consuming up to 90 grams of carbohydrate per hour will help you to sustain your performance and will prevent early fatigue.
Recovery Nutrition
There is no particular advantage to eating immediately after exercise, unless you are training twice in one day. Provided that you consume sufficient calories over the next 24-hour period, your muscles will recover for your next workout.
A combination of protein and carbohydrates post exercise will promote faster muscle repair and greater muscle growth, and can reduce muscle soreness. I’m an advocate of real food over commercial recovery drinks such as protein drinks, as they lack fibre, phytochemicals and other nutrients. However, if you’re rushed for time, a protein drink will contain adequate protein and carbohydrate for recovery.
Recovery continues well past the immediate post-exercise period so you need to continue paying attention to your diet and fluid intake. Protein manufacture increases over the following 24-48 hours, generally peaking after about 24 hours. If you don’t supply your body with adequate nutrients, you risk incomplete recovery and sub-par adaptation to training. Eat regularly spaced nutritious meals that deliver protein and carbohydrates along with fibre, vitamins, minerals and healthy fats.