The management of bodyweight is an important aspect for many athletes, none more so than those involved in weight-classified sports (e.g., boxing, rowing and wrestling). The premise of weight categories is to match opponents of similar size, strength and capability to ensure a fair contest.
It is common practice for athletes to compete in a weight class that is below their ‘normal’ training weight to gain an advantage over smaller, lighter opponents. Unfortunately, this has resulted in some athletes adopting extreme weight-loss strategies including the use of sweat suits, diuretics and laxatives.
More recently, sport scientists have advised athletes to train and compete at a bodyweight that is within 5% limits, such that it can be controlled by nutrition and hydration strategies that promote effective training, recovery and general health. Short-term losses of 2-3% bodyweight can be sustained over a short period of time, while it is accepted that if greater changes in bodyweight are required, a long-term weight-loss strategy is needed.
Short-term weight loss
If performance requires a reduction in bodyweight over a short-term period (days), athletes can safely sustain a 2-3% drop without fear of decrements in performance. This can be done through moderate energy restriction, slight changes in the residue content of food, in addition to mild restriction of fluid.
A traditional training taper, i.e., a reduction in training volume, characterises the days before competition. Energy intake needs to be reduced during this time to match this reduction in energy expenditure – otherwise weight gain will occur. At the same time, athletes will switch to low-fibre foods in their diet (i.e., a reduction of fruit and vegetables) to reduce the amount and volume of faeces removal.
Finally, mild dehydration as a result of natural sweat loss to exercise and/or fluid restriction is promoted. To do this safely and effectively, athletes will partially replace the fluid lost as sweat, and typically consume low-sodium fluids at time points between meals, thus reducing fluid retention that occurs when fluid is consumed with food.
Long-term weight loss
It is generally accepted that athletes should aim for a weight loss of up to, but not greater than, 0.5 kg per week. Typically, weight losses greater than this could result in a loss of lean body mass that would negatively affect an individual’s power to weight ratio. In some situations, it could also reduce metabolic rate and bone mineral density, and impair growth and development in young athletes.
The most important aspect of long-term weight loss is to ensure that good practice is maintained. A nutritional intake that supports a 0.5 kg per week weight loss still needs to support the demands of their training programme. As such, carbohydrates remain important, with a focus on nutrient-dense options that also provide other key micronutrients such as calcium and iron. Protein is important for growth and repair and is consumed in snacks to improve satiety (feelings of fullness) and reduce the potential loss of muscle mass.
Classically, athletes reduce overall energy intake by removing typical sports foods, but fail to appreciate the potential impact on performance. Athletes should look to reduce high-fat content foods, alcohol and generally the amount of food consumed at each meal, more so than skipping meals or taking whole foods out. Failure could compromise training, training adaptations, performance and increase the risk of infection.
Weight loss is a normal aspect of many sports, but needs to be managed carefully. Ideally, an athlete shouldn’t look to lose more than 5% of their ‘normal’ bodyweight, unless a long-term strategy is followed. In either circumstance, the diet still needs to deliver against the demands of training and competition, and consequently the general make up of the diet doesn’t change except for general manipulation of the overall energy intake over a 24-hour period.
Nick Morgan is a sport scientist with experience of working with elite and amateur athletes on physiology and nutrition. Nick is British Association of Sport & Exercise Sciences accredited, and is now a director of his own company, Sports Integrated.
The views and opinions expressed in this article are those of the author and not of Fitness Professionals Ltd or Virtual Magazine. Consult a qualified health or fitness professional before making changes to your diet or exercise.