Short rides often with lots of different work.
One day work over ground poles, another day work completely flat and on truly bending as you do figures (figure eights, circles,) another day work on lots of transitions from walk to trot (and reverse) trot to canter (and reverse,) lunge for 15 minutes one day and call it good.
Be sure to mix in some time down days too. But short riding time (with proper cool down and warm up) often, with off days, will help him lose weight.
Grazing muzzle would help him out a lot. Also look at his diet and make sure he isn't being over fed.
Cantering generally helps horses lose weight, trotting generally helps horses build muscle. Obviously paired together they do both but cantering generally takes a lot more stamina than trotting.
However don't push the horse too fast. Since he's overweight there is a lot going on with his joints so you need to be careful not to overdue it.
"Strength is the ability to use a muscle without tension"
Last edited by Skyseternalangel; 05-21-2012 at 12:57 AM.