There’s plenty of evidence showing how important nutrition is for exercise, from aiding performance to enhancing recovery. But it’s often confusing to know whether it’s best to eat before or after you exercise.
To answer this, you should first consider what you’re training for, as your goal could influence whether to eat before or not. Second, you need to consider the level that you’re at. An elite athlete’s needs are different from a beginner and probably influences how much energy from food is needed – and even the number of meals eaten. Third, you need to think about what works for you. Some people thrive when training in a fasted state, while for others, it’s the opposite.
When we exercise, our bodies need energy. This energy is supplied by fuel, either stored in our bodies (as carbohydrate in our liver and muscles, or from fat stores), or from the food we eat. If the exercise is demanding or if we exercise for a long time, we use more stored carbohydrate (known as glycogen).
Studies show that carbohydrates in our diet are important in topping up our glycogen stores between bouts of exercise and also when eaten before exercise sessions.
So if your energy is somewhat low, or you’re doing a longer or more demanding session, consuming carbohydrate-rich foods – such as pasta, rice, cereals or fruit – around three to four hours before exercise can help provide the energy you need to keep moving.
There’s also evidence that carbohydrate type can help improve metabolic responses to exercise. While this may not necessarily affect performance, eating lower glycemic index foods (foods that produce a slower-releasing carbohydrate effect, such as porridge oats or wholegrain bread) can better sustain energy and provide benefits (such as lower use of glycogen stores) during exercise for some.
But eating right before exercising could cause indigestion, cramps or nausea. Consuming an easily digestible, carbohydrate-rich meal (for example, porridge with blueberries) around three hours before a training session may help sustain energy and improve training quality without necessarily leading to gut issues. Pre-fuelling also helps sustain blood sugar levels during exercise, which can positively affect performance.
If your goal is building strength or muscle, evidence also suggests that eating protein before exercise may improve overall recovery responses. By providing essential amino acids before they’re needed, this could support early recovery and may be relevant for those undertaking intensive workouts.
On the flip side, however, recent research has demonstrated that training in a fasted state – for example, first thing in the morning before breakfast – can actually lead to positive adaptations linked with efficient fuel use and fat burning.
This doesn’t necessarily mean greater weight loss, but it could optimise fuel efficiency, which may be important for those training for a marathon, for…