Pushups: Pushing it to the limit

April Calderon recently pumped out 61 pushups in 60 seconds while balancing precariously on three medicine balls, a feat that has been submitted to Guinness World Records.

The key is "great balance, mental toughness, and lots and lots of practice," said Calderon, a general manager for three Anytime Fitness gyms in central Florida. "But I'm really sick of pushups right now."

Pushups, one of the best measures of upper-body fitness, are worth the pain. Traditionally, they're done while in a horizontal position -- hands and feet on the floor. But pushups, like many body-weight exercises, can also be made more or less challenging.

"They're a true resistance and core exercise," said Michele Olson, research director of the Auburn University Human Performance Laboratory in Montgomery, Ala. "They work every single muscle that you can name in your upper body."

In addition to the triceps and chest, research shows pushups also recruit the shoulder muscles, biceps and abdominals, Olson said.

In addition to resistance training, pushups are used to rehabilitate the upper body after injuries because they can activate the muscles that stabilize the shoulder blade and the shoulder joint, said David Suprak, an assistant professor of kinesiology at Western Washington University.

Calderon started with traditional pushups, progressed to an unstable surface -- a rubber dome mounted on a platform called a BOSU -- and then learned to balance on the three balls.

Traditional pushups

Start in a plank position with your body in a straight line and your hands just slightly more than shoulder-width apart. Tighten the abs as if bracing for a punch and slowly lower the chest toward the ground. Aiming at a target can help get the chest close to the floor, Olson said. Keep the stomach off the mat and the back straight. Narrower hand placement benefits the triceps and the chest.

Decline pushup

Elevating the feet makes the pushup harder. Use a low bench or a stair, which is about 5 inches tall, Olson said.

Pushup with knees down

Wall pushup

Place your palms against a wall, slightly wider than your shoulders with the fingertips pointing up. Back your feet away from the wall, about 20 inches. Lean forward, bending your elbows until your nose nearly touches the wall. Push back out to start. To make it harder, place your hands on a lower surface, such as the edge of a desk.

Incline pushup

Find a weight bench, or if you're outside, use a park bench. Place your hands on the bench and your feet on the ground. Lower your chest to the bench and push back up.

Minus a limb

Unstable platform

Medicine balls, stability balls, basketballs and BOSUs can all be used to decrease stability, working more muscles. Pausing at the beginning, end or middle of a movement will make it even harder. Some research shows unstable surfaces may increase the activation of the muscles that stabilize the shoulders, but studies are inconclusive. Wobbly surfaces will, however, definitely increase trunk stabilization, Suprak said. And the chest can drop lower than normal if you're on three balls, so be cautious about going deeper, Olson said.