Touching your toes is probably the most popular hamstring stretch-but it's also the most misunderstood. Too often, guys round their backs to reach their feet, and that takes tension off the hamstrings, limiting the stretch. Never learning to stretch your hams properly is dangerous. It can lead to feeling stiff and inflexible, and if your regimen includes a lot of running or leg-curl exercises, it can actually make you more prone to injury. Take this test to see how close you are to being hamstrung by your own fitness program, and then protect yourself accordingly.

Stand with your feet shoulder-width apart and your legs straight. Push your butt out behind you until you feel your lower back arch. Now pinch some skin next to your spine between the index finger and thumb of your right hand (the pinch should be parallel to the floor), and place your left hand on your abs [1]. Bend forward at the hips until you feel the skin begin to pull-this is your end range of motion before the lower back takes over [2].

You pass if you can bend 50 degrees or more. Any less, and you've got tight hamstrings. If you failed, use the test as a stretch from now on-bend as far as you can and hold the position for 30 seconds. That's one set. Do two to three sets, and lay off exercises such as leg curls and stiff-legged deadlifts until your range of motion improves and you can pass the test.