Pilates

Doing your best is a concept that has nothing to do with competition.
You are not competing with someone else.
You are not even competing with what you did last time, or any other time.
You are not trying to reach some arbitrary goal you set for yourself in advance.

What you are doing is putting your total attention and effort
into executing each motion
with the greatest degree of control and precision and
with the best coordination of breathing and movement
you are capable of at the time you are doing it.