Rethinking the Role of the Nordic Hamstring Exercise in Injury and Performance
There was a time when the Nordic hamstring curl (NHC) was one of the most popular exercises in hamstring injury prevention and rehab. Much of this was motivated by early prospective cohort studies, where lower eccentric strength during the Nordic was associated with an increased risk of future hamstring injury across sports such as AFL, football, and rugby [1-3]. Alongside this, injury prevention programmes incorporating the Nordic demonstrated large reductions in hamstring injury rates [4].
However, as with many things in sports science, the wheel turns and the picture becomes less clear.
Over time, several criticisms of the Nordic have emerged and adoption in many settings has turned out to be low [5]. Delayed onset muscle soreness and subsequent muscle fatigue is often raised as a major limitation to the exercise [6], particularly where it may interfere with the ability to complete high-speed running in subsequent days. Mechanically, questions have also been raised around what the exercise actually targets and its appropriateness in rehab. Electromyography (EMG) studies suggest the Nordic has a bias towards the medial hamstrings, with interventions shown to result in hypertrophy and architectural adaptations predominantly in the Semitendinosus and Biceps Femoris Short Head [7], rather than the Biceps Femoris Long Head which is most commonly injured.
At the same time, the evidence linking Nordic strength to injury risk has become less consistent. Systematic reviews now report mixed findings, with some studies showing associations and others not [8]. Many intervention studies have also been conducted in sub-elite or amateur populations, which limits direct translation to elite environments. Personally, and from conversations I have had with others, practitioners working with elite level athletes often report a similar observation; that some of the strongest athletes on Nordics are those who experience the most hamstring injuries.
So, this raises the question; does the Nordic hamstring curl have any relevance for rehabilitation and injury profiling?
A reductionist problem
One of the challenges here is how we interpret the role of individual muscles.
While the Nordic may bias the medial hamstrings, focusing only on the injured muscle (typically the long head of biceps femoris) risks becoming overly reductionist. Sprinting is not a single-muscle task. It requires coordinated whole body function, including coordinated action of the hamstring muscles with different muscles of the hamstring complex playing different roles across the gait cycle.
Across sprinting, the medial hamstrings appear to play an important role during the early-to-mid swing phase [9]. At higher knee flexion angles, the semitendinosus is well positioned to begin controlling the forward motion of the shank [10]. This may allow the biceps femoris long head to tolerate demands later in swing, closer to terminal extension.
This idea is supported by morphological data. When comparing elite and sub-elite sprinters, there are clear differences across the hamstring complex. Both the semitendinosus and short head of biceps femoris are substantially larger in elite sprinters (≈25–30%), than both non-elite and team sport athletes [11, 12]. Supporting the idea that these muscles may have an important role to play in distributing load during high-speed running, rather than letting the long head act in isolation.
What does the Nordic actually change?
There is also some evidence that the Nordic can influence sprint-related outcomes including performance, architecture and biomechanics.
For example, following Nordic training, increases in both hip extensor and knee flexor moments during the swing phase have been reported [13]. While also associated with increases in sprint performance [14] and increases in muscle fascicle length [15]. Which may reflect an improved capacity of the hamstring complex, not just to produce force, but to tolerate and coordinate force during the late swing phase, where injury risk is highest.
Programming matters
While muscle soreness is often raised as a barrier to use, in my opinion this potentially reflects a programming issue, rather than an exercise issue.
High-intensity eccentric work will create fatigue. But the key consideration is where it sits within the training week. Personally I place Nordics before rest days or lower-intensity sessions, away from high-speed exposures to allow adequate recovery between sessions. Additionally, even low volume training can result in adaptations [15], therefore graded exposure may help mitigate muscle soreness, while still developing the tissue itself.
Does the Nordic only target the medial hamstrings?
Not entirely. While early phases of the movement appear to favour the medial hamstrings, there is evidence that as the knee approaches more extended positions (later in the lowering phase), activation of the biceps femoris long head increases [16]. As already mentioned, architectural adaptations in this muscle have also been observed following Nordic training [15]. Therefore, its not that clear cut and gains in the long head can still be made. That said, if the specific goal is to target the long head of biceps femoris I would personally choose alternative exercise options.
So, is it still relevant?
Yes – just not in the way we like to think.
There is no single exercise that can fully address hamstring injury risk or performance. The Nordic may not be the most specific exercise for targeting the long head of biceps femoris, but it does develop aspects of the hamstring musculature that are relevant for sprinting.
Athletes who perform poorly on the Nordic have been shown, in some cohorts, to be at greater risk of injury. And this may reflect reduced capacity of the other hamstring muscles – particularly the medial hamstrings and short head – reducing their ability to assist the biceps femoris long head in managing load during high-speed running.
From this perspective, the Nordic hamstring exercise likely still has a role, but as part of a wider and more holistic approach. It can contribute to developing overall hamstring capacity, while also sitting alongside other methods of profiling that capture different aspects of function. Personally, it is best viewed as a complement to more targeted, position-specific exercises, rather than a standalone solution.
Take home
Ultimately, rehabilitation and injury prevention should reflect how the hamstrings function in sport; as a coordinated system, not in isolation. The Nordic hamstring curl is not a panacea, it does not fully represent the demands of sprinting, and is unlikely to be the most appropriate exercise for every aim. However, it remains a useful component within a wider profiling and rehab strategy. Combining exercises that target specific muscle–tendon demands with testing across a range of positions and functions can potentially better capture the complexity of hamstring muscle behaviour during high-speed running, and therefore better inform both rehabilitation and performance preparation.
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2. Bourne, M.N., et al., Eccentric Knee Flexor Strength and Risk of Hamstring Injuries in Rugby Union: A Prospective Study. Am J Sports Med, 2015. 43(11): p. 2663-70.
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9. Higashihara, A., et al., Differences in hamstring activation characteristics between the acceleration and maximum-speed phases of sprinting. J Sports Sci, 2018. 36(12): p. 1313-1318.
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11. Miller, R., et al., The Muscle Morphology of Elite Sprint Running. Med Sci Sports Exerc, 2021. 53(4): p. 804-815.
12. Kawama, R., et al., Sub-elite sprinters and rugby players possess different morphological characteristics of the individual hamstrings and quadriceps muscles. PLoS One, 2021. 16(10): p. e0259039.
13. Alt, T., et al., Nordic Hamstring Exercise training induces improved lower‐limb swing phase mechanics and sustained strength preservation in sprinters. Scandinavian journal of medicine & science in sports, 2021. 31(4): p. 826-838.
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15. Presland, J.D., et al., The effect of Nordic hamstring exercise training volume on biceps femoris long head architectural adaptation. Scand J Med Sci Sports, 2018. 28(7): p. 1775-1783.
16. Van Hooren, B., et al., Muscle forces and fascicle behavior during three hamstring exercises. Scand J Med Sci Sports, 2022. 32(6): p. 997-1012.