Title: The effect of high or low volume Nordic hamstring exercise training on eccentric strength and biceps femoris long head architectural adaptations
Question: How do high VS low volumes Nordics differ in their impacts on eccentric hamstring strength and BFlh architecture?
Key Takeaway: High-volume and low-volume training groups showed almost no difference between one another – both groups maintained strength and fascicle lengths at very similar levels. Perhaps a low volume of Nordics is enough to maintain positive adaptations?
Summary: Two groups of recreationally active males performed a six-week Nordic training program and a two-week de-training period. In the six-week training program, both groups started with a two-week moderate volume program. Then, for the remaining four weeks, one group completed a high-volume program (resulting in 440 reps over the six week program) and the other a low-volume program (resulting in 128 reps over the six week program). Changes in eccentric hamstring strength changes were monitored using the NordBord and changes in BFlh fascicle lengths were monitored using ultrasound.
- Both groups gained strength and fascicle length significantly within the first two weeks of the training program
- Both groups maintained strength and fasciscle length over the remaining four weeks of the training program
- Both groups’ fascicle lengths returned to baseline lengths after the two-week de-training period
- Implications: results suggest volume of eccentric stimulus may be less important than consistency of eccentric stimulus
At the outset, it is worth noting that this study was conducted on recreationally active males, and therefore may not be directly transferable to the elite population. This is compounded by the fact that participants were prohibited from other forms of hamstring resistance training exercise during the study, an unlikely situation within a professional sports environment.
Having said this, in leagues where games are scheduled at close intervals, there may be an inability to complete a full lower limb strength program, and therefore the findings of this paper emphasize the importance of the Nordic hamstring exercise (NHE) if we are looking for the best outcome from minimal exposure.
Alongside the effectiveness of low-volume NHE protocols, the other key point that I have taken from reading this paper is the importance of individualized prescription of the exercise. The authors screened the participants for an ability to maintain their NHE into the final 10-20 degrees of range (i.e. approximately 160-180° of knee extension). If they were able to hold the contraction close to end of range, then a weight was added to maintain the supramaximal aspect of the exercise (a method first used by Bourne, et al. (2016)). This may explain why the findings of this study contradict those of Seymore et al. (2017) who found an insignificant fascicle length change within their NHE protocol (though this study used female participants, which may contribute to the divergent results).
The outcomes of this article lead us to consider what we are doing within an elite environment, and how close to the prescribed doses from Presland, et al’s (2017) research we can get with a squad of elite players and minimal time. I have tried to summarise some key points/ideas below;
- We need to ensure consistency of our practice if we are to reap the benefits of the NHE. This is both in the physiological benefits as well as the impact that consistency of performance has on reduction of DOMS, an issue commonly cited as a reason for non-compliance.
- Low volume prescription appears at the very minimum to be sufficient in maintaining the early adaptations to a NHE Program.
- Exercise prescription in which each individual player is consistently reassessed for ability to progress (e.g. through addition of external weight) may be more effective in achieving and maintaining desired physiological outcomes.
- Knowledge that a moderate volume NHE protocol (4×6 reps twice a week) is effective at increasing Biceps Femoris fascicle length inside of 14 days means that we may look to incorporate this during the final two weeks of the off season where associated DOMS will have little impact. This allows utilisation of the low load (2×4 reps) protocol during the intense preseason period. This may help to mitigate risk of hamstring injury during the early stages of the season.
Bourne, MN, Duhig, SJ, Timmins, RG, Williams, MD, Opar, DA, Najjar, AA, Kerr, GK, Shield, AJ. (2016). Impact of the Nordic hamstring and hip extension exercises on hamstring architecture and morphology: implications for injury prevention. Br J Sports Med. 2016;0:1–11.
Seymore, KD, Domire, ZJ, DeVita, P, Rider, PM, Kulas, AS. (2017). The effect of Nordic hamstring strength training on muscle architecture, stiffness and strength. European Journal of Applied Physiology, 117(5), 943-953.