Sprinting is a stressful task for any athlete in any sport. However the idea that you will have less hamstring injuries by sprinting is not popular. Given that high speed running is the most common mechanism of injury, Askling et al, It was interesting to read a recent paper by researchers in Australia, Freeman et al, looking at hamstring eccentric strength and the implementation of sprinting or Nordic hamstring exercises as an intervention. Interestingly after four weeks of completing the sprint or Nordic exercises twice weekly, significant improvements in eccentric hamstring strength were observed in both groups. Additionally the sprint group improved maximum speed capabilities, whilst the Nordic hamstring group did not significantly.
This finding is very interesting for a number of reasons. It highlights that the commonly held notion that increased exposure to sprinting increases risk of hamstring strain injury is more complex and it also suggests that potentially the implementation of sprint training into athletic preparation has the potential to affect injury as well as performance.
Why does increased eccentric hamstring strength reduce injury risk?
Eccentric strength is the ability for the muscle to produce force while it lengthens.
A significant amount of research has been published over the last ten years by an Australian group of researchers that shows that there is a strong correlation with low eccentric hamstring strength and the risk of hamstring strain injuries. It has been validated across multiple studies and the implementation of Nordic or eccentric hamstring loading exercises into training programs has been shown to reduce the incidence of hamstring strain injuries, particularly in team sport settings.
With this in mind the recent paper gives credence to the idea that exposure to high stress activities if done in a systematic fashion has the potential to cause positive adaptation.
So should you include regular sprint training into your program to reduce your risk of hamstring injury?
The evidence is starting to suggest yes.