There will be some influence, but this influence is not essential, but refers to the "adaptation" process of the body to a state, such as the fatigue degree of the body, the level of nutrient intake, the quality of rest and recovery, etc. It is the same as the period when there is no fitness activity.

I don't know if you just took part in fitness training or are experienced exercisers. If you are the latter, your menstrual situation is obviously different from before. If possible, go to the hospital to check the reason. After all, you are 36 years old. Check to see if there are any other reasons for the reproductive system, so that you will have confidence.

Fitness activities are usually carried out. Different individuals and people with different training levels have different effects on menstruation, but they are all reflected in the adjustment of external changes within the body.

Your menstrual period may be prolonged because of insufficient physical recovery or excessive training intensity before menstruation. Of course, continuous training will stimulate some endocrine adjustment (estrogen and androgen levels at different stages), which should be basically normal, if there is no other discomfort you didn't mention.

No matter what season, you should keep your body temperature during and after training, and don't blow at fans and air conditioners. This will cause capillary contraction, which is not conducive to the renewal of blood oxides and metabolites, and is not conducive to the recovery of body fatigue.