From Exodus.
Remember the Sabbath day to keep it holy. For in six days the Lord God created the heavens and the earth, and the seventh day he rested. Therefore you shall not do any labor, you or your manservant or your maidservant....
---------------------------------------
The real question is "What brings glory to God?" If people's lives are so busy that they don't have time to get to the gym except for one day that's meant for rest and worship, that's their choice, but should you equip them in that decision?
[Edited on 7-18-2005 by ChristianasJourney]