#overstimulation

How do I know if I am adding too much to my little ones schedule?

This year we have the option of extending my son’s usual PreK day by an hour, taking him from 1:30pm to 2:30pm, where instead of that hour continuing to serve as his quiet/decompressing time from school at home, it would be replaced with an active activity like gymnastics/sports/dance.
Should I give him another semester where we honor his usual "quiet time" block and try adding that extra hour next semester, giving him a little more time to navigate his energy levels?
Or just proceed with the extra hour of school, knowing that kids are adaptable and will eventually adjust?