Watching What You Eat If You Are Active In Sports

I’ve met a number of people who believe that by exercising they need not worry about what they eat. Nothing could be further from the truth.

There are a number of reasons for watching what you eat if you are also active in sports:

  • In many, if not all sports your weight will affect your performance level. 
  • To train and compete successfully in your chosen sport you need to remain healthy. Choosing the correct foods has a big impact on your health.
  • Many sports require that you have sufficient reserves of mental concentration and physical energy. Diet plays a crucial role in keeping your energy levels in balance.
  • If you are training regularly for your sport you will need to ensure that you recover quickly from training sessions so that you gain the most from your efforts. The types of food you eat play a big role in this.

1. Performance and weight

Many sports involve moving your body either quickly with force, or less quickly, but over longer periods of time. Some involve both these things. Either way you do not want to be carrying too much extra fat or muscle in the wrong places. Where you store fat is pretty much determined at birth, and through puberty. Where you store muscle is determined by what types of exercise you do.

Losing weight

For most people losing weight will help them perform better.

Don’t bother counting calories. It is better to change your diet and consume foods that don’t destabilize your blood sugar levels, as this leads to storage of fat. Eat foods such as meat, eggs, fish, dairy, nuts, seeds and vegetables. Foods such as sweets, cakes, biscuits and too much pasta, bread and rice will lead to surges of insulin. Insulin is the hormone that allows fat to be stored around the body.

One example of a diet that can support this is the Paleo diet, which has been getting a lot of media attention over the last few years.

Gaining weight

Some people need to gain more muscle to be effective in their chosen sport. To do this, you need to boost levels of certain hormones such as insulin like growth factors and testosterone. This can be done by exercising hard and ensuring you get adequate recovery. However, some people benefit more from this type of approach, simply because they naturally have more of the hormones they need for muscle growth.

The solution for the less well muscled also includes a diet that stimulates the hormones needed for muscle growth.

2. Maintaining health

To improve at your sport, you need to train consistently over a period of time. Without long periods of good health this is impossible.

For most people the major issues are coughs, colds, stomach problems and injury. By eating the right foods and avoiding undue stresses we can improve our chances of staying in full health.


Recovery from hard exercise is one of the key factors. Ensure you don’t become dehydrated and low on energy if you are in danger of getting an illness. You need to consume the correct foods after training and competition. For instance, after long and hard efforts you need to top up your reserves of muscle fuel (glycogen) quickly to avoid depletion. This can be achieved by eating a full rounded meal within 1 hour of completing the exercise. Leaving it longer than this reduces the amount of glycogen you can store, and you then become run down over time.

Generally there are some foods that help maintain a strong immune system. These include:

  • Pro-biotic foods such as yoghurt and other fermented foods (natto, sauerkraut).
  • Pre-biotic foods such as leeks, Jerusalem artichokes, asparagus and potatoes cooked and left overnight feed the good bacteria that come from the pro-biotic products helping them to flourish. By consuming a diet containing both you will reduce your chances of suffering illness.
  • Anti-inflammatory foods such as fish oils that prevent your immune system over reacting to certain stressors.
  • Vitamins and minerals that are needed for your body to work properly. If you are training hard then you will need more of these than most other people. In particular vitamins A, D and K as well as minerals such as selenium and zinc all help to strengthen immunity.

You should not be surprised to hear that a diet containing plenty of vegetables and some fruit such as berries, along with nuts and seeds should help most people stay healthier.


Consuming anti-inflammatory foods can also help reduce the time spent injured. There may also be some benefit in taking supplements such as glucosamine, which show some ability to improve the condition of the joints. 

3. Providing energy for your sport

To compete in sport you need 3 things from your diet: energy, water and salt. If you exercise for less than 30 minutes you may not require any of these. However, the longer and harder you exercise the more likely you are to need to consume some food and drink.


Sugary drinks are used by many. This is better than nothing if you would otherwise fade and slow down, however long term consumption of these drinks rots your teeth, and if you are an endurance athlete it reduces your endurance capacity. Your body becomes reliant on the sugar and fails to utilise its own resources of fat and protein to fuel exercise. Your best strategy is to use as much sugary drinks or gels as you need, but no more. In fact, in training, it is best to challenge yourself from time to time by “going low”. To do this you exercise without much fuel and your body then adapts for future training sessions.

Don’t “go low” if you are competing however, as your performance will suffer.


You need to remain hydrated for optimal performance. However, many people consume too much water, especially in long distance events such as marathons. You can afford to lose up to 5% of your body weight in water without too much of a problem. Many top marathon runners do just this. However, if you can stay within 1-3% of your normal weight then you are probably within optimal limits. Drink when you get thirsty, or if you know you frequently get dehydrated then use a drinking schedule.

Don’t forget that how much you need is determined by your sweat rate which is strongly influenced by heat and humidity.


Salt is not an issue in most sports, but if you are sweating a lot then you can lose a lot of salt. It is also true that a little salt can help you absorb sugar more quickly to provide you with energy.

Some sports drinks provide salt and other do not. It is worth being aware of which do and don’t especially if you are exercising long and hard and likely to sweat a lot.

4. Adapting and recovering from exercise

There are specialised sports recovery products that you can buy. They are normally a mix of sugars and protein. While these are worthwhile if you out in the countryside, not close to any places where you can find healthy food they are not the best solution. You are best off eating a full meal containing protein, fats and carbohydrates within about 30 - 90 minutes after finishing your exercise. If you are feeling famished, then this is a clear signal from your body that you need to eat. Doing so will speed your recovery.

The views expressed in this article are those of the author. All articles published on Nutritionist Resource are reviewed by our editorial team.

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Milton Keynes, Buckinghamshire, MK16
Written by Robin Dowswell, BSc MFNTP
Milton Keynes, Buckinghamshire, MK16

Robin Dowswell is a Nutritional Therapist working just outside Milton Keynes in Buckinghamshire. He specialises in sports nutrition, as well as having a keen interest in using diet as a powerful tool to enjoy improved health.

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