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Your body composition, or body weight, can have a strong impact on your athletic performance in certain sports. The dos and don'ts of losing weight.

This article is presented by the Swiss Sports Nutrition Society

The quest for the ideal body weight is an «ongoing topic» and thus also a frequent training goal. Particularly when it comes to an athletic goal such as an autumn marathon, this topic always comes to the fore. In sports, a distinction should be made between short-term and long-term weight loss. Short term means «making weight», which is practised in sports with weight classes in order to be eligible to compete in a weight class on the day of the competition. This article, however, is about long-term weight loss and the goal of changing your body composition or body weight.

In theory, weight loss is very simple: the calorie intake must be lower than the calories burned. In actual fact, however, it is not always that easy to lose weight.

Loss in body weight or water weight?

As already mentioned, calorie balance has a direct influence on body weight. Other factors, such as the hormone status in women, water retention, or whether carbohydrate reserves in the muscles are full or empty also have a significant impact on our body weight. For example, if I eat a «low carb» diet one day and do a lot of sports, I may be 2 to 3 kg lighter the next day because I have emptied my carbohydrate reserves along with the water they retain. Even during the menstrual cycle my weight may vary due to hormonal fluctuations without actually increasing or losing weight. These fluctuations are more likely down to water retention.

If an athlete wants to lose weight without losing any muscle mass, maintaining an optimal or even increased intake of protein is of major relevance. With a severe negative calorie balance, the body will also «use» muscle proteins to cover its bodily functions and needs. It is therefore advisable to eat 1.8 to 2.7 g of protein per kg of body weight each day. You should also make sure that it is well distributed throughout the day (4-5 servings).

Do I need to train in the fat burning zone to lose fat?

The answer to this question is «no». In order to lose fat mass, it is not necessary to stay in the fat burning zone or even maximise it. As already mentioned, the calorie intake and associated calorie balance is much more decisive. With lipid metabolism training, however, you can introduce your body to a different stimulus. New stimuli force the body to react and adapt. The body can also get used to an extremely low calorie intake, for example, by letting its bodily functions run on the bare minimum. This certainly does not favour weight loss in the long term. If anything, the opposite is true, because you eat less and less and still don’t lose weight.

Practical implementation in everyday sports

• Athletes should eat good quality protein sources distributed over 4 to 5 units per day to cover the increased protein requirement for maintaining muscle mass.
• Drink sufficient fluids in the form of water or unsweetened tea to maintain the body’s hydration level (at least 2 to 3 litres plus compensation for the sweat loss during sports).
• The daily negative energy balance should not be greater than 500 kcal in order to lose weight in the long term and prevent the body from reducing its bodily functions or slowing down its metabolism.
• The intake of calories and carbohydrates should be adapted to the training programme as well as the overall expenditure to achieve the best possible performance and recovery as well as prevent injuries and infections, even in the case of energy restriction.
• Lipid metabolism training can be integrated as an additional factor in order to «force» the body to make adaptations. However, this should be done with care and always in relation to the actual competitive goal.

A specialist can provide optimal support with your individual preparation and during your weight loss by adapting the diet to your training plan and personal factors.