My OTTB is actually pretty hard to stay 'fit', he gains weight VERY easy.. If you put him out on good pasture for a month with light work, he'll get a good bit of fat on him. He has free choice grass with grain just twice a week, plus a mineral block, all Summer & he stays fit. During the winter he gets grain 4 times a week, free choice of hay & grass, plus alfalfa cubes.
Sit tall in the saddle, hold your head up high, keep your eyes fixed where the trail meets the sky, & live like you aint afraid to die, & don't be scared, just enjoy your ride.