Hamstring Injury and Performance
The hamstrings are the most injured muscle group in team sport, and the only one whose injury rate has risen steadily while the resources devoted to preventing it have also risen. That combination is worth taking seriously, because it suggests the problem is not a shortage of effort but a mismatch between what is being trained and what actually fails. This guide collects what we have published on the subject: what the hamstrings do during sprinting, why exposure to high speed appears to protect rather than endanger, how to judge an exercise, why proximal tendinopathy follows different rules, and how practitioners in several sports have described managing it.
Why Hamstring Injuries
Keep Increasing
Across twenty-one seasons of the UEFA Elite Club Injury Study the hamstrings' share of all injuries doubled, from 12 per cent in 2001/02 to 24 per cent in 2021/22, and between 2014/15 and 2021/22 incidence rose by roughly 4 per cent a year in matches and 7 per cent a year in training (Ekstrand et al., 2023). Most of those injuries occur during sprinting or high-speed running.
The common response has been to reduce exposure to the actions associated with the injury, on the reasoning that tissue which is not loaded cannot be overloaded. The reasoning is sound as far as it goes, and it is also incomplete: it treats the exposure as the hazard rather than asking what makes an athlete able to tolerate it. That is the argument developed in high-speed exposure in football, which is the reference article for this guide.
What the Hamstrings Do
During Sprinting
The mechanical demand that matters occurs before the foot lands, not after. During late swing the hamstrings are lengthening under load while decelerating the shank, and activation at that moment frequently exceeds anything recorded during stance (Schache et al., 2012). The muscle is required to produce high force at long length, at speed, in a window of perhaps a tenth of a second.
This dual role — braking the limb in swing, contributing to propulsion in stance — is why a single description of hamstring function tends to mislead. The distinction between the two, and the anatomical variation that means not all hamstrings behave alike, is set out in hamstrings behaviour and movement expression. The wider coordination that determines how much late-swing load is imposed in the first place belongs to sprint mechanics rather than to the muscle, and is covered in the guide to speed development and sprint mechanics.
Exposure as Protection
Rather than Risk
The counterintuitive finding in this area is that regular exposure to near-maximal running appears to be associated with lower, not higher, hamstring injury risk, while sudden increases in that exposure are associated with higher risk. The variable is not the presence of high-speed running but the relationship between recent exposure and accustomed exposure.
The practical consequence changes the question a practitioner asks. Rather than how much sprinting can be avoided, it becomes how regularly near-maximal running can be included so that the tissue is accustomed to it, and how to avoid the spikes created by a congested fixture period or a return from absence. Programming it across the training week, and rebuilding it after an injury, is the second half of high-speed exposure in football.
There is a measurement problem underneath this, and it is the reason the principle is easier to state than to apply. Most clubs track total distance and total high-intensity distance, neither of which isolates running close to an individual's maximum, which is the band that appears to matter. An athlete can accumulate a large high-intensity volume while rarely approaching the speeds at which the hamstrings are loaded hardest, and the monitoring will not show the difference. Establishing an individual maximum and then expressing weekly exposure relative to it is more work than reading a squad average, and it is the part that most often does not get done.
This is also where the rehabilitation literature and the prevention literature meet. An athlete returning from a hamstring injury who has not been re-exposed to near-maximal running has not completed the process, however well the strength measures have recovered.
Choosing Exercises, and the
Limits of Activation
Strength work has a defensible place: including the Nordic hamstring exercise in prevention programmes has been reported to approximately halve hamstring injury rates across a large pooled sample (van Dyk et al., 2019), and the mechanical properties that distinguish exercises — the muscle length at which force is produced, the contraction type, the velocity — give a reasonable basis for selection (Bourne et al., 2018).
The distinction that does most work in exercise selection is between knee-dominant and hip-dominant patterns, because the two load different regions of the muscle group and produce different patterns of adaptation. A programme built entirely on one of them develops a narrower capacity than its volume suggests, which is one explanation for why athletes who train hamstrings diligently still sustain injuries in late swing, where both the hip and the knee are involved simultaneously.
Surface EMG activation does not give a reasonable basis. An exercise can produce very high activation in a short-range, low-load position while replicating almost nothing of the late-swing demand, which is high force at long length under speed. Activation is a measurement of convenience, not of mechanical similarity, and a good deal of what circulates as hamstring training has been adopted on that basis. The critique is made in hamstring tantrums. A related case, the seated good morning, is examined in reconsidering the seated good morning.
Proximal Hamstring Tendinopathy is a Different Problem
Tendinopathy at the ischial tuberosity is not a muscle strain with a different name, and treating it as one tends to make it worse. The distinguishing feature is that the enthesis experiences compression as well as tension, and the compressive component increases with hip flexion. An exercise performed at a deep hip angle therefore loads the painful structure in the way least likely to help, regardless of how appropriate it looks for the hamstrings in general.
That single mechanical fact governs exercise selection, the staging of a loading progression and the prevention of recurrence, all of which are set out in proximal hamstring tendinopathy in speed-based athletes. The broader evidence on tendon loading, which applies here and to the Achilles alike, is in exercise interventions for tendinopathy. Distinguishing a strain from a tendinopathy, and both from referred pain, is a clinical judgement and it is the kind of question the sports medicine consulting work exists to support.
What Practitioners Do:
a 2018 Roundtable
In 2018 we ran a five-part interview series on hamstring management with practitioners working in different sports and different countries: Ken Crenshaw in Major League Baseball, Darcy Norman, Gustavo Pérez Solano and Andreas Beck in elite football, and Kostas Chatzichristos in elite basketball.
The series is presented here as what it is: a snapshot of applied practice at that time, not current guidance. Several of the positions in it predate the evidence discussed above, and the field has moved — most obviously on high-speed exposure, which in 2018 was more often treated as a hazard to be limited. Read with that in mind, the interviews remain useful in a way that a review article is not, because they describe how decisions were actually made inside organisations under competitive pressure, including the disagreements between them.
Ken Crenshaw on hamstring management in professional baseball · Darcy Norman on the performance director's role in football · Kostas Chatzichristos on elite basketball · Gustavo Pérez Solano and Andreas Beck on professional football.
Where to Start
Readers working in team sport should begin with high-speed exposure in football, which covers risk, programming and return to play in one place.
Readers who want the mechanics first should read hamstrings behaviour and movement expression, then hamstring tantrums for what follows from it about exercise selection.
Readers dealing with a painful tendon rather than a strain should go directly to proximal hamstring tendinopathy.
Full Reading List
High-Speed Exposure in Football, Part 1: Hamstring Injury Risk, Rehabilitation and Return to Play — why regular near-maximal running may protect, how to programme it across the week, and how to rebuild it after injury.
Proximal Hamstring Tendinopathy in Speed-Based Athletes — tension and compression at the ischial enthesis, staged loading, and preventing recurrence.
Hamstrings Behaviour and Movement Expression: The Great Debate — brake and spring, contraction type, and anatomical variation between individuals.
Hamstring Tantrums: Effective Exercise or Social Media Noise? — why EMG activation is a poor guide to exercise selection.
Related reading
Reconsidering the Seated Good Morning · Speed Training: A Systems Approach · Sprinting as a Coupled Locomotor System · Exercise Interventions for Tendinopathy
The Hamstring Management Series 2018
Part 1 — Ken Crenshaw · Part 2 — Darcy Norman · Part 3 — Kostas Chatzichristos · Part 4 — Gustavo Pérez Solano · Part 5 — Andreas Beck
Frequently Asked Questions
Does sprinting cause hamstring injuries?
Most hamstring injuries occur during sprinting, which is not the same as sprinting causing them. The available evidence points toward regular exposure to near-maximal running being associated with lower risk, and sudden increases in exposure with higher risk. On that reading the hazard is the change in exposure rather than the exposure itself, which is why withdrawing sprinting from a programme can leave an athlete less able to tolerate the sprinting that competition will impose anyway.
Is the Nordic hamstring exercise enough on its own?
It has the strongest prevention evidence of any single exercise, with pooled data indicating roughly a halving of injury rates when it is included in a programme. It is not sufficient on its own, because it trains force production at long length in a slow, knee-dominant pattern, while the late-swing demand is fast and involves the hip. Treating it as the whole programme rather than one component is a common way of doing the right exercise and still missing the demand.
Why does my athlete's hamstring hurt when sitting rather than when running?
Pain on sitting, and on deep hip flexion generally, is more characteristic of proximal hamstring tendinopathy than of a muscle strain, because sitting compresses the tendon against the ischial tuberosity. The distinction matters for treatment: exercises at deep hip angles that would be reasonable for a strain increase the compressive load on an irritated enthesis. This is a clinical assessment and should not be made from a description alone.
How soon can an athlete sprint again after a hamstring injury?
There is no interval that answers this independently of the athlete, and the more useful framing is that re-exposure to near-maximal running is part of the rehabilitation rather than something that follows it. A return-to-play decision based on strength testing and pain alone, without the athlete having been progressively re-exposed to high speed, leaves the demand that caused the injury untested.
Are high-EMG hamstring exercises useful?
High surface EMG activation indicates that the muscle is working, not that it is working in the way that sprinting requires. The late-swing demand is high force at long muscle length under speed, and an exercise can generate large activation in a short-range, low-load position while reproducing none of that. Activation is easy to measure, which is a reason for its popularity rather than a reason to select on it.
References
- Bourne, M.N., Timmins, R.G., Opar, D.A., Pizzari, T., Ruddy, J.D., Sims, C., Williams, M.D. and Shield, A.J. (2018) 'An evidence-based framework for strengthening exercises to prevent hamstring injury', Sports Medicine, 48(2), pp. 251–267.
- Ekstrand, J., Bengtsson, H., Waldén, M., Davison, M., Khan, K.M. and Hägglund, M. (2023) 'Hamstring injury rates have increased during recent seasons and now constitute 24% of all injuries in men's professional football: the UEFA Elite Club Injury Study from 2001/02 to 2021/22', British Journal of Sports Medicine, 57(5), pp. 292–298.
- Schache, A.G., Dorn, T.W., Blanch, P.D., Brown, N.A.T. and Pandy, M.G. (2012) 'Mechanics of the human hamstring muscles during sprinting', Medicine & Science in Sports & Exercise, 44(4), pp. 647–658.
- van Dyk, N., Behan, F.P. and Whiteley, R. (2019) 'Including the Nordic hamstring exercise in injury prevention programmes halves the rate of hamstring injuries: a systematic review and meta-analysis of 8459 athletes', British Journal of Sports Medicine, 53(21), pp. 1362–1370.