Body weight and running sport - how this is connected
World-class long-distance runners are usually lightweights. No wonder, the longer the distance, the more each kilogramme on the hips literally weighs. However, the smallest possible number of kilogrammes on the scales is not everything. It is all about finding the right mix of lightness and strength. If you keep cutting back on fat (and muscle), you may end up sacrificing leg strength or core stability.
In short, there is no such thing as the perfect runner's weight. As an amateur runner, you should not feel pressurized to become lighter and lighter. Instead, listen to your gut feeling. If your times are right and you feel good while running, there is no reason to save weight.
The situation is different for the so-called "mara-tonnis". Anyone who weighs 80 kilogrammes or more and is not exactly a giant will certainly know that their weight is not ideal for running. However, with continuous training and - how else could it be - a balanced diet, even these runners will gradually become lighter. On the other hand, those who are heavily overweight or have damage to their musculoskeletal system should first reduce their weight through sports that are easier for the joints (such as swimming or cycling) before lacing up their running shoes.
But what is the secret to losing weight? A simple formula: If you consume more calories than you eat, you lose weight. Accordingly, if you consume more energy than your body needs, you gain weight. Losing weight is therefore a question of energy balance. If it is negative, you lose weight.
But how do you know how many calories you are consuming? A large part of your daily energy needs is your basal metabolic rate. This is the amount of energy your body needs to fuel your muscles, brain and organs. The basal metabolic rate depends on individual factors such as age, height, gender and weight.
It can be roughly calculated using the Harris-Benedict formula.
Basal metabolic rate (kcal) = 655.096 + (9.563 x body weight/kg) + (1.850 x height/cm) - (4.676 x age)
Basal metabolic rate (kcal) = 66.473 + (13.752 x body weight/kg) + (5.003 x height/cm) - (6.755 x age)
A 170 centimeter tall, 78 kilogramme, 30 year old woman would therefore have a basal metabolic rate of around 1575 kilocalories.
The calories you consume through exercise must be added to this. The so-called work metabolic rate makes up about 25 percent of the basal metabolic rate for light physical activity, which you can add to the basal metabolic rate to determine your total calorie consumption. For moderate activity it is 50 percent, and for heavy physical activity you can add about 75 percent. So if our sample woman spends the day in the office and does no exercise, her total metabolic rate is about 2,000 kilocalories. On the other hand, if she walks to work, climbs the stairs instead of taking the lift, and walks for an hour after work, she will easily burn 3,000. If she does this two or three times a week, she will have a negative energy balance with a balanced diet and without major restrictions - and lose weight.
Now, one could argue that it is possible to lose weight without exercising at all. Our model woman would achieve a negative energy balance even without exercise if she could restrict herself to a daily calorie intake of about 1,400 kilocalories. In one week she would have more than 2,000 kilocalories less than she consumes, in one month more than 8,000.
But this method only works in theory. If you rely on reduction strategies, you have missed the point of evolution. As soon as you drastically restrict your energy intake, your body "thinks" you are in a famine. It cannot know that you are causing this by yourself. Instead, it switches to "stone age mode" and stores as much fat as possible. Before it releases this reserve, it first switches off all superfluous energy consumers and releases them for energy utilization. The muscles in particular are hit hard.
The deceptive thing is that in the first phase of the diet you lose weight. Especially since muscles are heavier than fat. The first kilo on the scales disappears quickly and the diet seems to be a complete success. But it is bad enough that you do not lose any fat - with every kilo of muscle mass you lose, your basal metabolic rate drops. This makes it more difficult to achieve a negative energy balance without exercise. This is the reason why many people return to their initial weight soon after a diet and even gain weight in the long run (keyword yo-yo effect).
So counting calories and restricting food intake cannot be the solution. The good news is that if you run regularly, you can always eat your fill. On the contrary, eating your fill on a regular basis is a must - as long as it is balanced. After all, you need energy for your training. And in keeping up with the ancient Greek understanding of dieting, only a long-term change in lifestyle will lead to permanent weight loss in the case of being overweight: get out of the armchair, away from the crisps, and towards running and conscious, healthy eating.