Go ahead: Talk yourself up, say professional trainer and researchers. In a test of vertical-leaping ability, people who said “bend and drive” out loud jumped higher than when they didn’t give themselves an instructional talk. The researchers say verbalizing the action may influence your brain’s cerebral cortex to activate more muscle fibers. As for those muscles, do box jumps: Squat, jump onto an 18- to 24-inch box, and then step down. Complete 3 sets of 5 reps, resting 3 minutes between sets.