Tricep Push-up :: Works triceps, chest, and core Get in plank position with your hands shoulder-width apart (A). Lower your chest toward the floor while keeping your upper arms parallel to your sides and your elbows pointing straight back (B). Push back up to start. That's one rep. Do three sets of 12 to 15 reps, resting for 30 seconds between sets. To make it easier, lower your knees to the ground. There's no shame in girl pushups!