Personally, I think it has a lot to do with environmental factors. First of all, regardless of the quality of the gym, people will have a lot of sweaty nights after fitness, and the gym is also a crowded place. People usually like to take a bath immediately after exercise, and a lot of sweat will be very comfortable to wash down with cold water.

But I don't know, at this time, your body has been slowly invaded by the disease, because you will catch a cold if you are not careful. If you catch a cold, it will do some harm to your immune system, so your resistance will drop at this time, which is normal.

Then there are a lot of people in the gym I just mentioned, and it is inevitable that others will bring in some bacteria and viruses from the outside world. Fitness equipment is shared by everyone. Many fitness equipment is not disinfected properly, and you will be infected through some contact or the spread of sweat droplets, which is one of the reasons why your resistance decreases through external viruses.

It is also to popularize a knowledge for everyone. If you take enough protein, sleep can make your muscles grow, and exercise just keeps them. These two things complement each other. Therefore, if you want to gain muscle, you must have absolute sleep, so that your muscles can grow more perfectly. And remember that excessive training will seriously overdraw your physical strength. Don't do this, especially after a cold. At this time, your body has not recovered. If you exercise suddenly, it will do great harm to your health. Remember to combine work and rest.