I am a sports student. Recently, the weather suddenly turned cold, and then the waist muscles were very tired. I don't know why.

Your waist muscles are tired, which has nothing to do with the weather. It should be fatigue caused by training.

Sports training pays attention to excessive recovery. After each training, the body needs to have a certain recovery time. If the recovery time is not enough, the body will start the next training without excessive recovery. Such long-term accumulation will cause excessive fatigue and affect the training effect. When it is serious, it will cause a significant decline in sports performance.

Solution:

First, reduce the intensity and amount of exercise during this period;

The second is active relaxation, massage, hot compress and so on.