If you can’t do a regular push-up on the ground – start this way. Use a high counter instead. Once you can master 5 reps with good form at the kitchen counter, move to a desk, then a stable chair, then the second step of a staircase, then you’ll be ready for the floor. And a push-up is one of the single best, full-body exercises you can do. It engages your abs, arms, and chest.