1. Muscle dissolution may occur after fitness.

2. It may lead to joint injury, because the human body bears a large load during exercise, which is easy to cause joint injury.

3. It may induce cardiovascular and cerebrovascular diseases, because a large amount of adrenaline will be produced in the body during exercise, leading to tachycardia. If it cannot be adjusted in time, it is easy to have sudden death.

4. If you don't pay attention after fitness, it may lead to excessive fatigue, causing backache, leg cramps, muscle aches and other symptoms.

5. Exercise may also lead to motor nerve injury and reduce motor function.

6. It may also lead to lactic acid accumulation after fitness, causing symptoms of body aches.

These are the six possible side effects of fitness. Therefore, we must make reasonable arrangements and choices according to our actual situation to avoid adverse reactions and side effects, which will be counterproductive. At the same time, warm-up activities can be carried out properly to improve the flexibility of ligaments and reduce the strain during fitness.