A year ago, 42-year-old Ms. Li made up her mind to attend a slimming and bodybuilding training class because of her constant weight gain. After training for more than half a year, the body mass index has not decreased, but has increased. Ms. Li is very depressed when she thinks of the intensive training that has been sweating for the past six months. She can't understand: why is Ms. Wang, who came to the training together, getting slimmer and slimmer, but still bloated? Does exercise to lose weight have no effect on me?
In fact, the reason why Ms. Li has such a situation is because the intensity of exercise is too great, not that exercise to lose weight has no effect on her. It can be said with certainty that exercise is effective for anyone to lose weight. The key is that the way and method of exercise should be correct, because exercise to lose weight has a "personality".
As we all know, heredity is a common factor leading to obesity, and the inheritance of muscle fiber type is closely related to weight loss effect. Physiologically, the types of muscle fibers in human body can be divided into two types: type I and type II, and type II muscle fibers can be divided into three types: Ⅱ A, Ⅱ B and Ⅱ C. Different people have different types of muscle fibers.
Type I muscle fiber is a typical slow red muscle, which is good at aerobic oxidation for energy supply. People engaged in endurance sports, such as excellent marathon runners, have a high proportion of slow muscle fibers in their bodies. When people with a high proportion of slow muscle fibers exercise, the way of muscle energy supply is aerobic oxidation, and the energy required for aerobic oxidation is mainly provided by glucose and fat. Therefore, people with a high proportion of slow muscle fibers have a relatively good effect of losing weight through exercise. However, it should be noted that the utilization rate of sugar is obviously higher than that of fat in aerobic exercise, and the energy supply ratio of fat can reach a higher level only in the process of aerobic exercise 1 hour or more. Therefore, people with a high proportion of slow muscle fibers, no matter what kind of exercise they take, must persist for more than an hour in order to achieve better weight loss.
Type Ⅱ B muscle fiber is a typical fast white muscle, which is good at supplying energy through anaerobic energy supply system. People who engage in speed sports, such as excellent weightlifters, have most fast muscle fibers in their bodies. With the increase of exercise intensity, for people with high proportion of fast muscle fibers, the proportion of anaerobic glycolysis energy supply will also increase, and the raw material for anaerobic glycolysis energy supply can only be sugar rather than fat. Therefore, if people with a high proportion of fast muscle fibers adopt high-intensity exercise, they will not consume fat, but will obviously increase lactic acid, an anaerobic glycolysis product of muscle glycogen. After lactic acid is produced, it can be oxidized and decomposed in the liver, and at the same time, it can be used as raw material to synthesize fatty acids again in the liver, resulting in fat accumulation in the body. This is also the reason why Ms. Li is getting fatter and fatter through exercise.
Of course, it does not mean that people with a high proportion of fast muscle fibers will be thin, and people with a high proportion of slow muscle fibers will be thin as soon as they are thin. Because people with a high proportion of fast muscle fibers also have a small amount of slow muscle fibers, as long as they make good use of low-intensity long-term exercise, such as jogging, long-term swimming, ballroom dancing, yangko and so on. They can still lose weight successfully. In addition, people with a high proportion of fast muscle fibers also have a small amount of aerobic oxidation when the exercise is very small and the heart rate is 100- 120 beats/min, but it needs to last for a certain time. For people with a high proportion of slow muscle fibers, if the exercise intensity exceeds a certain level (when the heart rate is greater than 150 beats/min), the proportion of anaerobic glycolysis energy supply will also increase, which will obviously increase lactic acid in the body and may also cause fat accumulation.
So, how do you know the content of muscle fiber in your body? Generally speaking, those who can do fast sports, such as playing tennis, don't last long, only last for a few minutes, or even feel tired after a few minutes, or after a period of exercise, their calves tend to thicken, suggesting that the proportion of fast muscle fibers in the body is high. On the contrary, those who can continue to exercise for a long time, and their calves are not easy to thicken after exercise, suggest that the proportion of slow muscle fibers in the body is high.
In short, exercise to lose weight has a "personality" effect, and different people have different ways and means. Therefore, before exercising to lose weight, it is best to self-evaluate the types of muscle fibers, or you can go to a professional institution, such as the Department of Exercise Physiology of the Institute of Physical Education, to make a functional evaluation, and then decide the intensity, time, frequency and events that should be taken.