Any vegan sprinters/fast twitch athletes here?

Ok so ive been listening to vegan calisthenics expert Frank Medrano for advice on getting ripped and he says that he does sprints for about 20 mins for cardio.

Today was my first day ever doing them. Its been about an hour since my workout and my heart is pumping a lot quicker than usual, my legs feel extremely weak, and ive got double charlie horses. Is this normal? Will my body become used to this eventually?