In P.E. I believe in the Play 60 motto that the National Association for Sport and Physical Education (NASPE) has adopted. The days your student have P.E. they should be close to obtaining playing 60 minutes. That will not be everyday of the week so, sports or just playing outside will have to fill the gaps.
I am leaving the Why Can't I skip 20 minutes of reading below from when I was in the classroom because reading is a great thing for many students to do after calming down from an increased heart rate or playing.