Strength training is used to form a perfect body, to lose weight and to build muscle mass. For the strenuous movements during weight training, the organism needs energy, which it gets from food. The food in turn consists of three major groups of nutrients: Carbohydrates, proteins and fats.
They are also called macronutrients and provide the body with the necessary calories. There are also micronutrients such as trace elements, minerals and vitamins. The energy (kJ) of foods is also expressed in calories (kcal).
However, the amount of calories is different for the three macronutrients. One gram of fat contains about 9.3 calories, while one gram of carbohydrates or protein has only about 4.2 calories. How many calories a person ultimately needs each day depends on several factors such as age, gender, his or her professional and sporting activities, digestion and muscle percentage in the tissues.
In strength training, it is definitely important that the athlete takes in enough calories. If the calorie intake is insufficient, the organism would rather lose muscle mass, especially during intensive training. Similar to endurance training, a lot of calories are burnt during strength training.
The calorie consumption during one hour of strength training can be up to 600 kilocalories, depending on the body stature, the breaks during training, the type of training, the weights used and the training intensity. A man who is 1.80 meters tall and weighs 100 kg has a calorie consumption of approximately 150 calories during a strength training session when lifting light weights during one hour. With heavy weights and intensive training, this figure can rise to up to 300 calories.
Many sport studios and Internet portals offer consumption calculators, which are to compute the calories burned with the weight training. It makes sense to determine this in order to calculate the ideal calorie intake. So the sportsman can be sure that he takes up neither too much nor too little energy with the food.
In addition to the factors of gender and height, the current weight is also decisive for calculating the calorie consumption. The more body mass a person has, the more calories he can burn through exercise. In later years of life, calorie consumption slowly decreases; this is also true for strength training.
This is due to the fact that from the age of 25 onwards, the proportion of muscle in the total body mass decreases and therefore less energy is burned. Independent of this, the intensity of the strength training also determines the calorie consumption. It is estimated that one hour of intensive, strenuous strength training consumes around 600 kcal.
Sometimes this is even more than can be achieved with endurance sports such as jogging or swimming. Strength training with several large muscle groups is most effective. They consume particularly large amounts of energy during sporting activity.
However, muscles do not only burn calories during weight training, but also at rest. People with a very high proportion of muscles therefore also have an increased basal metabolic rate – that is the amount of calories they need to “run” the body daily without any particular strain. Strength training is also attributed a particularly high so-called afterburning effect. Even after training, the energy requirement is still increased because carbohydrate stores are replenished and waste products have to be broken down and muscles built up. This process can be supported by light, protein-rich food after training.