1.** Heart problems * *: Excessive physical activity may lead to heart overload, which may lead to various heart problems, including myocardial infarction and arrhythmia.

2.** Physical injury * *: High-intensity training may cause injuries to muscles, bones and joints, especially for those who have not been properly trained.

3.** Malnutrition * *: If high-intensity training is combined with strict diet control, it may lead to malnutrition and affect the normal function of the body.

4.** Psychological problems * *: Excessive weight loss pressure may lead to psychological problems, such as anxiety and depression.

5.** Decline of immune system * *: Long-term intensive training and malnutrition may lead to decline of immune system function and make the body more susceptible to illness.

Therefore, whether you lose weight or keep fit, you should adopt a healthy and scientific way. Proper exercise and a balanced diet are the key. If intensive training is needed, it is best to do it under the guidance of professionals to ensure safety.