We have the same programme here in Scandinavia. The celebrities are pushing themselves much to far. Some of them start totally out of shape and train 6 days a week for 4 or 5 hours.
I'm a runner, and no beginner's running programme recommends training with 10k every day in order to run a half marathon in 2 months.
I do a bit of ballroom in the wintertime and I think people tend to forget that dancing is a sport and the same rules apply as to any other sport, which is warm ups, gradually working up stamina and strength, having days off between and listening to you body's signals, tretching.
It's depressing to be laid off due to an injury especially if it's something one enjoys.
And by the way running and dancing is a very good combination - so dancers: Take op running to, and get some fresh air!