Take a look at Ben Johnson’s world record 100-meter sprint. Although temporary in the record books, his performance was outstanding! No doubt, Ben Johnson is one of the greatest sprinters of all time, and his coach, the late Charlie Francis, was one the best in the business.
If you watch Johnson’s face throughout the race, it’s relaxed (i.e., his mouth and forehead are relaxed with his cheeks swinging side to side). That’s exactly what Francis advocates on page 13 of his book Training for Speed. There’s a reason sprinters are told to relax their face: it improves performance.
Well, a relaxed face doesn’t only improve your ability to sprint, it improves your ability to lift weights as well. Not only will you be able to lift more, your flexibility will improve too. Check out this video with strength and conditioning coach Charles Poliquin and you’ll see what I mean:
Release the tension around the jaw and tension in the whole body releases. It’s an instant gain in flexibility! Imagine what clenching your teeth can do during a workout? Forget about the fact that it can wear down your teeth (that’s why some people wear a mouthguard when they train), it’ll make you stiff.
Take-Home Message: To maximize your performance in the gym, relax your face when you lift.