Exercise on Shabbat
How would you explain why my rabbi says not to exercise on Shabbat, although I find it fun and relaxing?
The Aish Rabbi Replies:
What is "fun and relaxing" is usually permitted on Shabbat, but not always. (Driving to the beach is not permitted.)
Actually, if a person is exercising for enjoyment, it is permitted to exercise on Shabbat. This is because there is a special mitzvah called "Oneg Shabbat" -- which means a person should do what is enjoyable on Shabbat.
One should he careful, however, not to get sweaty and overexerted, because that goes against the spirit of rest and serenity that Shabbat is designed to provide. (Code of Jewish Law - O.C. 301:2, with Mishnah Berurah 7; "Shmirat Shabbat" 1:16:39)