Seldom can music performed by the original artist be used in group fitness classes or videos, because the beats per minute must be controlled and consistent, the rhythm must be consistent, and the phrasing must be in an even 32-count format because of the choreographed nature of the workout. Most original artists vary all of these components to make for an interesting musical experience; the song is the thing. There are numerous aerobics music companies that produce songs from sound-alike artists so that you feel more like you're working out to the original song; however they are produced for even rhythm, bpm and phrasing - the workout's the thing.
I like Cathe's music, myself. I trust her judgment on the music for the upcoming series as well.
A-jock