1. Muscle fatigue: Fitness requires a large number of muscle groups. If the fitness intensity is too high or the fitness time is too long, muscle fatigue and lactic acid accumulation will cause muscle to bend temporarily.
2. Muscle tension: In the process of fitness, muscles will be in a state of tension, which may lead to muscle spasm or bending.
3. Excessive exercise: Excessive exercise leads to muscle fatigue and soreness. In this case, muscles may also bend.
4. Incorrect posture: If the fitness posture is incorrect, such as using incorrect weight, posture or movements, it may lead to muscle strain or injury, which may cause muscle bending.
The next day may also be due to incomplete muscle recovery, fitness needs a cycle. It is generally recommended to have a proper rest and recovery within two days after fitness, so as to better carry out the next fitness.
If this situation persists for a long time or the symptoms worsen, it is recommended to seek medical advice in time.