Hamstring injuries in sprinters: how to lower your risk

How common are hamstring injuries in sprinters?

At the elite level they are the most frequent diagnosis. Physicians reported every injury at 16 international championships between 2007 and 2015, and hamstring injuries made up 17.1% of them. Men got them about twice as often as women. Over 14 championships from 2007 to 2018, the sprints accounted for more injuries than any other discipline (24% of men's and 26% of women's), and thigh muscle injuries were the main diagnosis in sprinting.

Before the 2018 European Championships, 48% of 357 athletes surveyed said they had had at least one hamstring injury, and 24% had had one in the previous season.

When in the stride do hamstrings get hurt?

The leading explanation is late swing, the moment before your foot touches down. Your shin is swinging forward fast, and the hamstrings have to brake it while they are being stretched. In a simulation study of 12 runners, the biceps femoris carried more load during swing than during stance at top speed, and the hamstrings did their negative (braking) work only in swing. Schache and colleagues happened to be recording an athlete who strained a hamstring mid-sprint, and the timing of the body's reactions put the injury in terminal swing.

A 2019 review weighed this against the case for early stance, when ground forces are high. It concluded that most of the literature points to late swing while noting that nobody has caught the mechanism directly. Training the hamstrings to handle hard eccentric work at long lengths is the logic behind the Nordic curl.

Risk factors with evidence

A previous hamstring strain

A 2020 meta-analysis pooled 78 studies with 8,319 hamstring strains in 71,324 athletes. Any history of hamstring strain raised risk 2.7-fold, and a recent one 4.8-fold. Older age, a previous ACL injury and a previous calf strain also raised risk. Age and prior injury were the strongest factors.

Low eccentric hamstring strength

Measured during the Nordic exercise, low eccentric strength predicted injury in Australian footballers (a 2.7-fold risk below 256 N at the start of preseason) and in elite soccer players, where short biceps femoris fascicles also raised risk. In rugby union, low strength did not predict injury, though a left-right imbalance of 15% or more did. Treat strength as one factor among several. In the footballer studies, high eccentric strength reduced the extra risk that came with age or a previous strain.

Sudden jumps in high-speed running

In two seasons of GPS data from an Australian Football League team, players who ran more high-speed distance than their usual in the week before were more likely to strain a hamstring. Regular exposure at a steady level looks different, as the top-speed section below shows.

Fatigue

In English professional football, hamstring strains rose toward the end of each half. A 2020 review found that fatigue can change how the hamstrings and surrounding muscles coordinate during sprinting, which may raise risk, but the evidence on how is incomplete.

Pelvic tilt

One prospective study of 60 soccer players linked more anterior pelvic tilt and trunk side-bending during the swing phase to a first hamstring injury. That is a single small study in another sport, and no trial has shown that changing your pelvic position lowers risk.

Nordic hamstring curls

Kneel on a pad with a partner holding your ankles, or hook your heels under something solid. Keep your hips straight and lower your body toward the floor as slowly as you can, catch yourself with your hands, and push back up to the start. All of the training effect comes from the slow lowering.

The injury data are strong. A meta-analysis of 15 studies and 8,459 athletes found that prevention programmes including the Nordic cut hamstring injuries by about half (risk ratio 0.49). A soccer-only meta-analysis found the same 0.49. In a trial of 942 Danish soccer players, the Nordic group had 3.8 acute hamstring injuries per 100 player-seasons against 13.1 in the control group, and recurrences fell from 45.8 to 7.1. Much of this evidence comes from soccer. A 2022 study of European Championship athletes called for more research into whether hamstring training protects track athletes.

Most Nordic studies use a progression first published in a 2004 Norwegian trial. The Danish soccer trial used a 10-week progressive programme, then one session a week through the season.

If three sessions a week is more than your sprint schedule can carry, the evidence supports a lighter dose. A meta-analysis of 13 studies found low-volume Nordic programmes produced strength and fascicle gains similar to high-volume ones, as long as they ran for at least 6 weeks. In one of those studies, this low-volume group gained as much as the high-volume group:

The same study found the longer fascicles shrank back within two weeks of stopping, while strength held for at least four. Keep a weekly maintenance dose going through the season. Do your Nordics after the sprinting, on the days you already lift, so the hard eccentric work comes after your fast running.

Regular exposure to top-speed running

In one season of GPS data from an elite Gaelic football squad, players who reached more than 95% of their maximum velocity at least once in training had lower odds of lower-limb injury than players whose top exposure was 85% (odds ratio 0.12). Both too little and too much maximal-velocity running raised risk. Taken with the Australian football data, the pattern is to sprint fast every week and add volume in small steps.

A review of elite sprint training lists 50–150m of maximal-velocity sprinting per session, with reps stopped when speed drops. The speed training guide shows how to space those sessions, and sprint workouts has flying sprints written out rep by rep. After a break, build your top-speed volume back in steps before you race.

Warm-up and session order

The injury evidence for warming up is weaker than you might expect. A systematic review of five randomised trials found three where a warm-up reduced injuries and two where it did not, and its authors judged the overall weight of evidence to favour warming up. Every fast session should start with one, and the sprint warm-up guide gives a 15–20 minute routine ending in build-ups to near top speed.

Fatigue may play a part, so put your fastest running early in the session while you are fresh, and stop a set when your times slip. Lifting and Nordics come after.

Common mistakes

Starting Nordics at full volume

The research progressions open with one session of 2 × 5 and take four weeks to reach three sessions a week. Follow that build.

Stopping Nordics in season

Fascicle gains reversed within two weeks of stopping in one study. One short session a week holds them.

Avoiding top speed to stay safe

Rare exposure to maximal velocity was linked to more injuries. Sprint fast every week and build volume in steps.

A big week after time off

Sudden spikes in high-speed running raised hamstring risk. Return to your usual volume in steps.