●Zui Zui, Master of Nutrition and Food, Jiangnan University
At the ancient Greek Olympic Games more than two thousand years ago, athletes ate very simply: olives, bread, cheese, and some meat. However, these ordinary diets did not prevent people in the ancient Greek era from having a strong body. Famous sculptures "The Discus Thrower" is a good example.
Today's urbanites are entering the gym one after another to achieve the purpose of strengthening their bodies through physical exercise. A latest survey by Brazilian scientists published in the June 2010 issue of the American Journal of Nutrition showed that among thousands of respondents, 36.2% took some nutritional supplements while working out, with the proportion of young men The highest, mostly for the purpose of supplementing nutrition or improving muscle mass.
For fitness people, protein is the most common nutritional supplement. Many people will take some protein powder or muscle-building powder after working out in order to achieve immediate strong effects. The protein content in these supplements is very high, even reaching 90% in pure protein powder. But are these really effective? ?
Normally, protein is rarely used for energy supply. However, when muscle glycogen is depleted after exercise, the energy supply function of protein increases, which indeed helps muscle repair and growth. But after all, protein is not the main energy substance. It is not advisable to consume too much, otherwise it will increase the metabolic rate. Ammonia, the metabolite of protein, is a toxic substance. It needs to be converted into urea by the liver and then excreted with the urine through the kidneys. This increases the burden on the liver and kidneys and depletes the body's water and calcium, causing dehydration and decalcification, leading to osteoporosis.
The muscle volume that bodybuilders focus on is not entirely determined by the amount of protein intake, but also related to the method, content and amount of exercise. The daily protein requirement for normal adults is about 1 gram per kilogram of body weight. Athletes need to properly supplement protein to make up for the body's consumption, but ordinary fitness people cannot compare with professional athletes in terms of exercise intensity and volume.
Nutritional supplements are not meal replacements. No one can expect to become as powerful as Popeye after eating spinach. The International Olympic Committee emphasized in its consensus statement on sports nutrition: “When the amount or type of dietary intake is limited, nutritional supplements may have a short-term effect, but attention must be paid to their energy efficiency, cost, and health risks before taking them. "Most people who exercise regularly at the gym can basically eat normally. And once a certain nutrient is excessive, it may also damage the bioavailability of other substances and cause overall malnutrition. Therefore, instead of supplementing with additional nutrients, we should pay more attention to daily meals, so that we can experience healthier results during exercise.