Exercise best on an empty stomach?

If you exercise at 6am, should you eat breakfast before or after gym? And if you go to gym after work and only get home after 7pm, must you eat supper?

Different levels of exercise

To answer queries about the timing of meals before or after exercise, it is necessary to differentiate between top, elite athletes and "the rest of us" who do exercise, but certainly not at the same intensity or for long periods of time.

We also need to differentiate between the goals of exercise: in the case of elite athletes, they exercise to hone their performance, to shave a millisecond off their sprinting time, to "make weight", to build specific muscles etc.

It is, therefore, logical that an elite athlete, who is either practising strenuously and/or competing, needs to have a very specific meal and beverage programme worked out for his or her specific needs.

For "the rest of us" who go to the gym at various times of day or night, or go running or cycling, there are certain rules that can be applied to the timing of pre- and post-exercise meals.

Early morning

Many people get up very early in the morning to fit in a gym session or a run before they go to work. The question is if they should eat anything before they exercise, or not?

The basic principle is that anyone who has eaten an evening meal at about 7 pm, who spent the evening doing various things and then slept for seven or more hours, will probably have fasted for 11 to 12 hours by the time he or she gets up in the morning.

After such a prolonged fast, your blood-sugar levels are very low, which will influence how much exercise you can do, how well your brain works and how tired you will feel during the rest of the day. It is, therefore, essential that you should eat something when you wake up to boost blood-sugar levels.

It's not necessary to eat a large and complex breakfast, but you do need to eat a light, balanced meal or snack before you start the day.

Examples of meals that will boost your blood-sugar levels and activate your brain include:

  • breakfast cereal or muesli with milk or yoghurt, honey or brown sugar, a fruit and tea or coffee
  • fruit with yoghurt, tea or coffee
  • wholewheat or rye toast or seedbread with cheese, peanut butter, a boiled egg or jam, tea or coffee
  • smoothies (made with milk or yoghurt, fresh fruit and honey)
  • Bokomo Up&Go Liquid Breakfast Cereal
  • an energy bar with a hot beverage

(Use fat-free milk or yoghurt, and fat-free cottage cheese if you're trying to lose weight.)

Any one of these breakfast examples will give you more energy when you exercise early in the morning.


Once you've had your small breakfast to activate your brain and blood sugar, and finished your workout, you'll probably need another snack during the morning to sustain you until lunchtime. If you go to work, pack a second breakfast snack for 10 am.

This snack could consist of any of the above-mentioned foods or additional sandwiches (use protein fillings such a lean meat, tuna, cottage cheese or egg), fresh or dried fruit, nuts, fat-free yoghurt, cheese wedges, energy bars or instant oats with a handful of raisins.

Evening meal

Those of us who don't exercise early in the morning, but rather pop into gym or go for a run after work, also often experience problems with supper. You may feel full and satiated after exercise, or be too tired to still prepare a meal. It is, however, just as important to eat something after exercising in the evening.

Eating after exercise will help your body to replenish its energy stores, which get depleted during exercise, and thus prevent you from feeling tired and washed out.

A tip is to have an energy drink just before, during and/or after exercise such as Energade, Powerade or any one of the many energy-booster bars or drinks (they should consist mainly of carbohydrates, not proteins) that are available. These will help your body to replace its energy stores.

Also wait until the satiating effects of exercise have worn off before you eat a meal at night.

If you're tired after a long day at work, followed by a strenuous bout of exercise, then make something simple and fast, or cook ahead the day before you go to gym.

Examples of light, easy, post-exercise meals include:

  • instant or regular pasta with canned tomato and onion sauce - add a tin of drained tuna (canned in water) if you are extra hungry
  • instant or regular pasta with an instant sauce and feta or grated cheddar cheese
  • cottage cheese with fresh fruit and vegetables
  • drained tuna with fresh salads and fruit
  • lean cold beef cuts or cold chicken with salads and fruit or pasta or rice (boil the day before and just reheat)
  • ready-to-eat dishes from your supermarket, such as pasta with sauce or meat or fish with vegetables
  • healthy take-aways such as filled pita or Nando's grilled chicken with salad

If you're very organised, you can also cook double quantities on the days when you don't go to gym. Store the meals in the fridge for the next day when you know you'll be tired and rushed.

Eating before and after exercise is an important facet of your routine, so take a little time to plan how you're going to achieve this. It may require you to buy a few additional foods (instant cereals or muesli, fruit, vegetables, prepared meats or salads, cottage cheese, ready-to-eat or take-away meals etc.) or cook ahead of time, but it will be worth it over and over again.

If you make plans to eat before and after exercise, you'll feel much more energetic and be able to exercise without falling asleep at your desk or passing out with tiredness or getting irritable because your blood-sugar levels are rock bottom. – (Dr Ingrid van Heerden, DietDoc)

- (Health24, updated September 2011)

Any questions? Ask DietDoc

Read more:

Lunch-time workout
Carbo facts and exercise
Eat breakfast to lose weight

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