Sport and Nutrition: A Winning Duo To Lose Weight
Sport and weight sometimes seem indissociable, whether it is a person who wants to get into sports to lose some or an athlete who pays attention to his weight. We give you some tips to reach your objectives…
The importance of weight in sport
In several disciplines such as running and cycling, we must move his weight. Moreover, excess weight increases the risk of injury and especially of joint problems. It is therefore sometimes interesting to adapt your diet to maintain or lose weight.
There are also sports based on weight categories such as weightlifting, judo, boxing … A few grams too many are synonymous with category changes or even disqualification. On the contrary, a few grams absent during the weighing seriously mortgage the chances of victory.
Finally, many women and young athletes put their health at risk in order to succeed in their discipline. Synchronized swimming, dance, gymnastics are part of these sports. Aesthetics occupy a central place in these sports, many competitors do not eat enough to stay slim.
Does sport change taste?
One hypothesis that runs: our energy reserves used during the exercise could play on our taste for this or that food. But there is no evidence that exercise induces food preferences (1). In the longer term, however, physical activity would be associated with a preference for carbohydrates. But it is not known whether these changes are determined by biology or psychological reasons. Thus, getting into sports, even suddenly, would not upset the behavior of food.
The sport gives hungry
Muscles Dig the Appetite
If you have converted to sport just recently, do not worry if you eat more even on days when you do not exercise. Indeed, the regular practice of a sport leads to an increase in the basic metabolism. Basal metabolism is the caloric expenditure of a person at rest in order to maintain the vital functions: the senses, the cardio-respiratory apparatus, the digestive apparatus … etc. It usually accounts for nearly 70% of energy expenditure, an average of 1200 calories in women and 1500 calories in men. Why does sport increase basic metabolism? Because physical activity increases muscle mass. Now muscles need eight to ten times more energy than fat to function. So you can eat more without getting fat.
The sedentary people who start to play sports are hungry
Physical exercise plays on the blood levels of a hormone: leptin. It is a molecule produced by adipose tissue (2) to signify to the brain that the reserves of fat are at their ideal level. Leptin, once released, causes a sensation of satiety by informing the brain that it is no longer necessary to eat.
The sedentary people who suddenly make an intense effort see their appetite increase (3). At issue is a severe fall in leptin, which therefore sends fewer signals of satiety. A sedentary person can therefore gain weight because of leptin and intense and too isolated exercise. On the other hand, if a sedentary person decides not to stop in such a way, his appetite will decrease during the sports sessions. Indeed, leptin levels will return to normal as regular sport does not influence leptin concentrations. As a result, since leptin is not affected by frequent efforts, everyone can train regularly without fear of offsetting energy costs.
Does sports make you lose weight?
Contrary to a widespread idea, doing sports is not enough to lose weight easily. Indeed, sport does not involve large energy costs. A jog at the speed of 8 kilometers / hour makes spending about 80 calories per kilometer or 640 calories in an hour. To lose 1 kilo, it is necessary to run at this pace for 12.5 hours.
But even if he does not lose weight on his own, sport is a very good ally to lose weight … Indeed, exercise firstly allows you to lose weight in the short term (4). However, this is hard to evaluate as exercise causes body changes and we must be careful not to confuse water losses due to dehydration and weight loss.
There is a tendency to compensate for the energy expended
Unfortunately for those who want to lose weight, we tend to eat more to offset the energy expenses. This compensation, which can last up to 16 days, allows us to take back all that was lost during the exercise or only a part. Studies that took place over one or two weeks found that it was very much dependent on the people being assessed: some were more “compensatory” than others. Some volunteers did not eat enough to offset the expenses of sport as long as they were less than 120 calories per day. But, this is true in the other direction as well: active people who are forced to adopt a sedentary routine do not necessarily reduce their food intake to balance intake and energy expenditure.
Do Abs to Lose Belly?
Doing abdominals does not decrease abdominal fat. Indeed, there are no blood vessels, therefore direct exchanges, between the fat under the skin and the muscles. When the abdominal muscles work, they do not only use fat from the fat accumulated under the skin of the belly: they can not only lose weight in this region. But, doing abdominal exercises nevertheless allows you to reduce all of the fat reserves and tone up your abdominal muscles. And it’s the same for the thighs!
What kind of sport to lose weight?
Want to lose weight via sport? For this you must try to carburize to the maximum with lipids. The most frequently given advice: do not go too fast and run long, lipids being then much used by the muscles. Indeed, the lower the intensity of exercise and the more muscles prefer lipids to the detriment of carbohydrates. From 40 minutes of effort, the use of lipids is multiplied by 5, which represents 12 to 15 grams of fat per hour of sport against a usual use of 4 grams.
But exercising at too low intensity does not allow you to spend a lot of energy. The researchers think that it would be necessary to do intense exercise but not too much to lose weight! The solution proposed by scientists: doing sport intermittently. That is to say that you chain intense efforts with calmer phases. This strategy provides the advantages of a long effort and an intense effort. For example, instead of running an hour try running 2 times 30 minutes. As a result, you may burn less fat during exercise, but the energy needed to maintain vital functions, resting metabolism, is increased (5). The amount of fat that will be “burnt” during the hours following the workout will be even greater when the exercise has been done at high intensity and the muscles have used a lot of carbohydrates (6).
Thus, it is rather the continuous and high intensity sessions or the long sessions including peaks of effort at very high intensity that cause the most important weight loss.
(1) King NA, Tremblay A, Blundell JE. Effects of exercise on appetite control: implications for energy balance. Med Sci Sports Exerc. 1997 Aug; 29 (8): 1076-89 (Psychology Department, University of Leeds, UK)
(2) D. Gomez-Merino, M. Chennaoui and CY Guezennec Leptin and physical exerciseLeptin and exercise. Science and Sports. Volume 19, Issue 1, February 2004, Pages 8-18
(3) Cintra DE, Ropelle ER, Pauli JR. Brain regulation of food intake and expenditure energy: molecular action of insulin, leptin and physical exercise] Rev Neurol. 2007 Dec 1-15; 45 (11): 672-82. Brazilian)
(4) Blundell JE, Stubbs RJ, Hughes DA, Whybrow S, King NA. Does physical activity stimulate appetite? Proc Nutr Soc. 2003 Aug; 62 (3): 651-61
(5) Tremblay A et al. Physical activity and weight maintenance. Int J Obes Relat Metab Disord 23: S50-4.
(6) Folch N et al. Metabolic response to small and large 13C-labelled pasta meals following rest or exercise in man. Br J Nutr 85: 671-80.