Menstruation is natural process of the body. It’s not something for which you need to stop your daily routine. About strenuous exercise, you can tone it down if you feel exhausted and the bleeding is heavy in initial days. But if you are a person who exercises regularly then I wouldn’t suggest to stop that all together. You can reduce the magnitude maybe. But keep your well hydrated and eat healthy. Stay stay, stay healthy.

Need detailed history and evaluation

It's better to avoid stress to your abdomen during your first 3 days of periods.. later once the bleeding is less u can start .

I would advice you not to.