Building Hindquarter Muscle

I knew that this would apply to either western or english. I have a 5 year old gelding that I ride 6 days out of the week. He is in perfect shape, very* healthy. I don't have any inclines, hills or sand. I want to know how to fill in that place on his rear end with muscle. I ride western if that helps. P.s. I do back up everyday numerous times because it was suggested to me by an old cowboy friend of mine.

Thanks ahead of time:))

If he's broke to rope, you can drag logs or anything else heavy off him at a walk. That builds their butt up just as well as working hills.

Though if he's not broke to rope, I wouldn't suggest trying it without training him to rope. I've been hurt bad a couple times trying to work a horse on the rope that either wasn't ready or wasn't broke (like I was told he was LOL).

For example, this tire is what I use to "log" my horses in preparation of roping.

Trot work helps to build hind muscle, especially if they are properly engaged and not hollow. It also aids in building up the back muscle too.

All that plus it builds aerobic fitness, something that obviously walking only won't really do.

Trotting poles and jumping (on the lunge if you don't jump yourself)

Thanks you all:) I will definitely start trotting more (with and without poles) and will try out the "log" thing:) I really appreciate it!!