It should be because the intensity of exercise at once is a bit large, which is not suitable. Just get used to it. I suggest the following:

1 Apply cold water to leg pain and hot water to ligament strain.

Ask a friend to help you relax your ligaments, or pat your small (big) legs on both sides.

Just stick to it for a few days.

Keep exercising every day, and you won't be so prone to acid.