Your hammies bend your knees, extend your legs, drive you up hills and power finish-line kicks. In fact, they do pretty much everything except hand you your sports drink, so when theyâ€™re too tight or weak to perform, you notice it.
Seven per cent of Runnerâ€™s World survey respondents said their hamstrings have bothered them in the past year. Counterintuitive as it might seem, very flexible people are prone to hamstring issues because their overly stretched muscles are more vulnerable. If you can barely touch your toes, stop looking smug â€“ youâ€™re also at risk.
Sitting for long periods is another risk factor, as is muscle imbalance: many runnersâ€™ quads overpower their hamstrings, which sets them up for injury.
Can you run through it?
If the pain comes on strong and suddenly, and the area bruises, you may have a pull and need months of rest. If itâ€™s a less severe overuse injury, you can usually run â€“ but itâ€™ll take time before youâ€™re on green again.
Running an easy pace is usually less painful than intervals or hill reps. Cycling, aqua running and swimming are alternatives.
Strengthen your hamstrings with single-leg hamstring curls (raise the bar with both legs, then slowly lower it one leg at a time) and single-leg deadlifts (stand on one leg with the other in the air behind you, keep your back straight and reach your hands towards the ground). Merrill recommends using a foam roller to alleviate tightness.
Prevent a relapse
Build with bridges: lie on your back with your feet on an exercise ball. Raise your hips, then lift one leg into the air. Lower your hips back down. Repeat with your other leg. Wearing compression tights post-run can also help by aiding blood flow.
When champion miler David Torrence felt his hamstring tighten, he took the next day off and went to his chiropractor. â€œI took it easy, iced the hamstring four times daily, and it improved within a week,â€ he says.
How to proceed
Stop running: You feel a sharp, sudden pain, especially with a â€˜snapâ€™ or a â€˜popâ€™. You experience bruising.
Run with caution: Chronic achiness and tightness that forces you to slow your pace and shorten your stride.
Go run: Pain-free on hills and speedwork â€“ even after long periods of sitting down.