Radio WFMU and Free Music Archive propose mixes of creative commons workout tunes for non commercial use.
As noted by WFMU Jason Sigal, these are good for schools, non profit fitness centers and other organizations who can’t pay the (pumped up) price to do squats to an original Britney Spears song, and are not too interested either in getting cheaper mock up versions of it.
So get into comfortable clothes and grab some for your community:
WFMU/FMA CC Workout mix
Remember no one actually has to become super better or optimized or anything, although, for those who like, a Mister Universe kind of workout is also available: The Arnold Schwarzenegger’s Total Body Workout MP3s