Master the Treadmill

Starting Up
Place your feet on the base of the treadmill, just wide of the belt, and set the incline at 1, which, on a treadmill, is equal to level ground, says Corey. (The 0 setting is actually a slight decline.) Program the belt to move at a slow walking speed—say, 3 miles per hour. Judge how fast the belt is moving, then step on, gradually increasing your speed.

The Sweet Spot
“A good guide to where you should be on the treadmill is where the side handles start to turn down toward the ground,” says Corey. If you’re behind the handles, you’re too far back and risk falling off the end of the machine. If you’re too far forward, your feet may hit the plastic at the front of the belt—and send you tumbling off the back. Not safe—or cool. No side rails? Stay as centered as possible, and look straight ahead to stay balanced. “Your body will follow your eyes,” says Corey. “If you’re looking at your feet, you’re going to start to sway. Pick a spot on the wall and stay focused.”

If you do lose your balance, hit the emergency stop button ASAP.

It’s All About Form
Bad form isn’t just about looking goofy—it’s about safety and performance, too. “Running with poor form will cause you to run out of energy faster, because you’re not being efficient,” says Corey. Plus, it puts added stress on joints and could predispose you to injury. If your treadmill is positioned in front of a mirror, check yourself out every once in a while. Here's what to look for:

Upper body

Run “tall” with your back comfortably straight. Slouching places undue stress on your joints and shortens your stride, making you take more steps to cover the same distance, which uses more energy and slows you down. Take a deep breath, and your back will naturally start to straighten. Also: Don’t let your shoulders creep toward your ears. Look straight ahead, and keep your chin level, not tucked into your neck or pointed toward the ceiling.

Arms 

Bend your elbows at 90-degree angles, and keep your hands in unclenched fists. Swing your arms forward and back, not across your body, which subtracts from your body’s forward motion. The more you move your arms, the faster your feet will carry you forward.

Feet

With each step, land between your heel and midfoot, and quickly roll forward and off the ball of your foot. This will prevent you from slapping the belt with flat feet, which jars your knees, hips, and back, and could lead to injury.