1. It doesn't mean how strong it is every day. As the saying goes, running water is not the first, but it is endless. A little every day, just stick to it. This can not only balance work and study, but also enhance physical fitness.
2. The ways of exercise can be running, swimming, playing ball and skipping rope. You can choose one or several you like and stick to it for a long time. Among them, swimming is the most joint-friendly exercise, and I hope it will be adopted.