Feeling your hamstrings tighten up as you run can really put a downer on your sprinting speed. Your hamstrings play a big role in your sprinting performance as they're responsible for flexing your knee, extending your hip and generating a significant amount of power and force to propel you from the ground. It's vital your hamstrings function optimally for you to sprint at your best.
Tight hamstrings are fairly common and are often caused by prolonged periods of sitting, according to the American Council on Exercise. Not stretching after running or sprinting can also lead to tight hamstrings. Perform either the lying hamstring or modified hurdler stretch to relieve tightness. For the former, lie on your back, lift one leg up in the air with your knee straight. You can either have a partner push it back, or wrap a towel around your foot and pull it foot toward your head. For the modified hurdler stretch, sit on the floor, extend one leg out in front and reach for your toes.
Tight or shortened hamstrings may not actually be the reason your hamstrings feel tight. Many runners don't maintain a neutral position when running, which can lead to tightness, according to running coach James Dunne. Tight hip flexors and weak core muscles are generally identified as the causes of hamstring tightness, so work on strengthening your core and stretch your hip flexors before and after every session. Do this by assuming a half-kneeling position and pushing your hips forward until your feel a stretch in your hip flexors.
Neural inhibition refers to a muscle's ability, or lack of ability, to perform a movement. This means a muscle can feel tight and lack movement, but the cause is actually that the muscle just isn't active, or used to moving in that way. Many people struggle to touch their toes, notes trainer Tony Gentilcore, and while tight hamstrings may appear to take the blame for this, it's actually caused by an inhibited motor pattern. To get your hamstrings moving as they should again, Gentilcore recommends first standing with your toes on a 2x4. Raising your toes shifts your base of support from the mid-foot to the heel and automatically activates your hamstrings. Hold a ball between your thighs and squeeze them together. Reach up in the air, then try to touch your toes. When you reach a sticking point, stand up, take a big breath in and repeat the process. Within 10 minutes your hamstrings should be firing properly and you'll be able to touch your toes.
Strength imbalances can play a role in sprinting performance and hamstring tightness. If your hamstrings are weak, they may fatigue quickly, which can make them feel tight. Strength coach Joe DeFranco recommends including hip thrusts, kettlebell swings, good mornings and sled drags in your workouts to build hamstring strength. Make sure your program is balanced, with roughly an equal amount of hamstring, glute, quadriceps and core exercises, along with regular stretching for each muscle group.