I heard this advice when I walked into my first yoga class years ago: to keep your jaw and neck relaxed, place your tongue on the roof of your mouth. But this tip has a broader application. Since you can't clench your jaw or grimace with your tongue is purposefully place there, this simple move is great for strength training. It will help remove unnecessary tension from your face, neck, chest, and shoulders. Michael Mejia, an exercise adviser for Men's Health, thinks placing your tongue on the roof of your mouth aids head alignment during crunches, thereby reducing neck strain. Having tested it, I agree. Try it next time you work out.