Good summary article on recent developments in fitness studies. This is specifically about interval training, which we've discussed here before. This short, intense interval method is also called Tabata training. It's very effective when done right but I would not go so far as to say that it's fun. By interval 6, you'll be trying to convince yourself to quit.
But what about for horses? Could we improve their fitness by doing some all-out sprints?
"After resting for four minutes, the students pedaled hard again for another 20 to 30 seconds, repeating the cycle four to six times (depending on how much each person could stand), “for a total of two to three minutes of very intense exercise per training session,” Gibala says."
I think the problem for using this with horses is the "depending on how much each 'person' could stand" problem. Pushing to an edge when you don't know exactly where that edge is could be very dangerous to the horse. Especially since I think there is a pretty good understanding with horses that the faster they go the higher the likelihood of injury. I would also wonder at the effects of conditioning are on the other tissues that needs to be conditioned.
I think I'll let someone else try it with their hoses first...