The nordic curl works and almost nobody wants to do it

The best evidenced hamstring intervention in team sport keeps failing at the only point that matters, which is compliance.

There is an exercise that roughly halves hamstring injury rates in squads that actually perform it, costs nothing, needs no equipment beyond a training partner holding your ankles, and takes four minutes. Adoption across professional football has been, generously, patchy.

The mechanism is not exotic. Most hamstring tears happen in late swing, when the muscle is long and lengthening under a big load, trying to decelerate the shin before the foot lands. That is an eccentric action at long muscle length. The nordic curl is an eccentric action at long muscle length. It increases eccentric strength, and there is decent evidence it adds sarcomeres in series, shifting the length at which the muscle produces peak force. Both changes point the same way.

So why does it not get done. Because it hurts, and because the soreness it produces two days later is severe enough that a fitness coach who introduces it in a congested week will be blamed for a flat performance on Saturday. The exercise has an immediate cost paid by the person prescribing it and a delayed benefit that is invisible, because a hamstring that did not tear is not an event anybody notices.

That is the real problem, and it is an incentive problem rather than a physiology one. Nobody is ever congratulated for the injuries that did not happen.

I would add two honest qualifications. The dosing in the original studies was probably higher than necessary, and much of the protective effect seems to arrive with modest volumes once the muscle has adapted, so the brutal introductory blocks that put players off may be avoidable. And the exercise is not a complete answer, because sprint exposure itself protects the hamstring, and a squad that never runs at full speed in training will keep tearing regardless of what it does on the mats.

What irritates me is the substitution. Clubs that will not do nordics do bridges, band walks, foam rolling, and a machine curl at a length the injury never occurs at, then report that they have a hamstring programme. They have a hamstring routine. It is not the same thing.

The intervention is cheap, evidenced and unpleasant. Sport keeps choosing pleasant and expensive.