Warm-up before participating in sports or physical activities. Studies show that failure to prepare the hamstring adequately results in a greater risk of injury. Take the time to do some mild aerobic exercises, such as jumps or stair stepping to increase blood circulation to the hamstring.
Stretch before and after your physical activity. Stretching before allows the hamstring to contract and relax with a smooth, fluid motion during your activity. After you're done, stretching keeps lactic acid from building up in the muscle and causing it to contract and cramp.
Start a hamstring program that includes sprinting and other high-velocity exercises. Every muscle has a "memory," and when you participate in sports where your hamstring contracts with explosive speed, you develop its memory strength, helping you run faster and jump higher.
Use weights and isometric exercises to strengthen your hamstring. Instead of building velocity, you'll be increasing power. Try the reverse leg curl machine at the gym, using a medium weight and doing five sets of six to eight repetitions.
Keep your hamstring hydrated to reduce the risk of injury. Your body is comprised of 70 percent water. When you're dehydrated, your muscles contract, making them more susceptible to injury. Drink plenty of water before, during and after physical activities.
Balance your hamstring mobility by strengthening your quadriceps. Muscles work in sets of two, one contracting while the other relaxes. In your thigh, both of these muscles are needed for optimal movement. However, avoid strength training both muscles on the same day.