Swimming provides a good workout for the whole body and is a great way to keep fit and healthy. As a competitive sport, training can involve a mixture of endurance and sprint training, depending on distance. Competition races can last anywhere between 20 seconds and 15 minutes, containing multiple heats over the course of the day. This places unique considerations on how swimmers should fuel the body for training.


Eating in the morning...

If you're going for a swim first thing, or have a training schedule that starts very early in the morning, fuelling your body for the task ahead can be a challenge. The horizontal body position in the pool, makes gastric influx more of an issue as well. It is therefore impractical to consume large amounts of food close to training, which otherwise may be more tolerable in cycling or running.

If you are new to swimming, eating properly and at the right times can help you develop your strength and cardio fitness all the more quickly. If competing, fuelling for training is vital for optimal performance. The main fuel for exercise is carbohydrate, which is then stored in the muscles and liver as glycogen. The body is only able to store a relatively small amount of carbohydrate, which is why keeping it topped up is so important. As it is difficult to eat and effectively digest food during swimming, the emphasis is placed on eating before and after exercise to maintain energy stores, especially if swimming more than once a day.

Question 1:

How long after eating a meal should I wait before going swimming?

Jerk sweet potato & black bean curry

Everyone has different levels of comfort regarding eating around swimming, so it is important to trial what works for you. In general, allow 2-4 hours before your swim, following a larger meal to allow for digestion, and 30 minutes - two hours for a smaller snack.

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Consider the Glycaemic Index (GI) of carbohydrate - A food’s GI measures how quickly it is digested and broken down into glucose. Lower GI foods, give a slower release of energy and should be the focus of main meals during training. High GI foods are quickly broken down to glucose and thus are more readily available for energy. These make great options for quick snacks, before, during, or after training

In general, main meals should include foods with low-GI carbohydrates and be moderate in protein and fats.

Good options include:
Prawn & pink grapefruit noodle salad
Brown rice stir-fry with coriander omelette
Spicy root & lentil casserole​
Jerk sweet potato & black bean curry
Smoked haddock with lemon & dill lentils

Often work or other commitments will dictate when you can get to the pool, meaning that only a quick snack before your swim may be possible. For energy boosting snacks before a swim, try to focus on smaller, higher GI carbohydrates, which will be quickly absorbed and place less strain on the gut.

Good options include:
- 500ml bottle of commercially available isotonic sports drink
- 1.5 carbohydrate energy gels
- Small handful of jellied sweets
- 1 large banana
- 1 large cereal bar or carbohydrate based energy bar (low fibre)

Question 2:


Should I eat before an early morning swim and if so, what should I opt for?

You should eat where possible before your morning swim; especially if it's a longer (one hour in duration) or a high-intensity session. The body uses carbohydrate stores for high-intensity work, and if training on an empty stomach you might find you tire quickly. Many recreational and competitive swimmers find eating before swimming difficult, due to experiencing symptoms of reflux or even nausea in the pool.

Here are two morning situations to plan for:

The early riser - if you wake up two hours before your swim, good options include:
Apple & linseed porridge
American blueberry pancakes
Honey muesli with raspberries & hazelnuts
Smoked salmon & pea frittata
Banana yogurt pots

Straight out of bed - if you prefer to get straight down to the pool, the energy-boosting snacks listed in question 1 would be good options.

If you can’t tolerate any food before your swim, or prefer not to eat, try increasing the carbohydrate portion of your evening meal the night before, as this will be stored in the muscles (as glycogen) ready for your morning swim.

Question 3

What should I definitely avoid eating before a swim?

To provide sufficient fuel, foods should be predominantly high in carbohydrate. Swimmers should also use foods they are used to, make them feel comfortable, and don’t cause any gastrointestinal symptoms.

In the 2-4 hours before, swimmers should try to limit the following, as these are well known causes of gastrointestinal distress (diarrhoea, bowel upsets): Excess fibre, excess fatty foods, unusually spicy foods, excess caffeine intakes, and more obviously, alcohol. In the hour before a swim, snacks should focus on smaller, easily absorbed, high GI snacks and contain limited amounts of fibre.
Now you know what to eat before your swim, get the rest of your training nutrition right:

What to eat during your swim
What to eat after your swim
What to eat before your run
What to eat during your run
What to eat after your run

Are you training for an event this year? Share your tips and experiences below.


As a sport and exercise nutritionist, James Collins regularly provides comment and consultation within the media and maintains a role of governance within health & nutrition in the UK, where he sits on The Royal Society of Medicine's (RSM) 'Food and Health' Council. He was heavily involved in advising Team GB in the run up to the London 2012 Olympic games, and now towards Rio 2016.

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