What to eat before exercise
What and when to eat before you work out is often the biggest dilemma you will face when you take up exercise. It seems so simple, but then you find that your favourite snack causes stitch or you are flagging after the first five minutes of effort. Get it right and your pre-exercise diet can make all the difference to your enjoyment and performance in sport. Here’s how:
When to eat:
For most people, a substantial snack 2-4 hours before a workout or run will see them through with few problems, whereas you should stick to a light snack if you have only an hour to spare. This timespan allows for food to be digested, metabolised and available for use by your muscles as energy when you need it. However, the precise time varies from person to person and none of us is the same. What works for your training partner or gym buddy might not work for you, so practice different approaches before deciding on your own pre-workout plan. Leaving it longer than 4 hours is inadvisable as the energy available from the meal is likely to have been used up, leaving you energy depleted before you even get going.
What to eat:
Carbohydrates are key for performance. There is no escaping the fact that they are the optimal and most efficient fuel for your body. But you need to select the right sort of carbs for optimum results and those with a low glycaemic index are top choices for your pre-workout meal as they provide a slow, sustained energy release. Porridge is a favourite of elite sports people (Paula Radcliffe and Mo Farah swear by it) and has been proven in studies at Loughborough University to provide a more effective burst of energy than commercial energy bars and gels. Sweet potatoes, brown rice and wholegrain bread are other choices. Including a little protein – eggs, cheese or milk – enhances the meal and makes it more palatable. If you are short on time, then you should be able to tolerate a light snack (a bagel, some plain popcorn, a banana or a fruit smoothie) 30-60 minutes before a workout.
What to drink:
Staying generally well hydrated before exercise is key. Clinical recommendations produced by the EFSA (European Food Safety Authority) say we need 35ml of fluid per kilogram of our bodyweight on a daily basis, before we do any physical activity. For most people, that equates to 8-12 cups a day or 2 litres for women and 2.5 litres for men. It doesn’t have to be water, but every expert favours it over other drinks, not only because it is calorie and additive free, but because it is accessible and cheap – especially if you stick to water from your tap. You won’t need sugary (isotonic) sports drinks unless you are planning to exercise hard for longer than 60-90 minutes and they will only add unnecessary calories if you use them in regular workouts. Don’t overdo your fluid intake. Experts are now concerned as much about exercisers drinking too much as too little. In an updated consensus statement published in the Clinical Journal of Sport Medicine in 2016, it was stressed that exercisers should drink only when they need to, not before. Dr Mitchell Rosner, a kidney specialist from the University of Virginia school of medicine, and a panel of 16 independent experts from four countries, encouraged a reliance on listening to your body. “We recommend using your thirst as a guide,” Dr Rosner said. “If you drink when thirsty, you will not become hyponatremic and you will not suffer from significant dehydration.” A guideline is around 500ml of fluid an hour during exercise.
Peta Bee is Performance Editor of Athletics Weekly magazine (www.athleticsweekly.com). She has degrees in sports science and nutrition