I should think something like :
All those people running on travelators or cycling along virtual kilometers...
Maybe it should be sane to go back to nature and leave those rooms to practice sport outside ?
What's the use of running in front of a TV ?
What's the purpose of such a behaviour ?
But actually, I do think something like :
oof oof oof... still 18 minutes left...
oof oof oof... still 17 minutes and 30 seconds left...
oof oof oof... still........................................................