You cannot recruit a sprint fibre in a gym

Hamstring programmes keep failing because slow, heavy strength work does not reach the tissue that tears at top speed.

The tear happens in late swing, at a speed the athlete reaches perhaps twice a week and only for a second. That awkward fact sits underneath every hamstring prevention programme ever sold.

Muscle is recruited in order. Low-force efforts bring in the fatigue-resistant fibres first, and the fastest, most fragile units only join when the demand is high enough, or the movement fast enough, to require them. A slow, heavy, controlled exercise can generate large forces, and it does build tissue, but the pattern of recruitment is not the pattern of a stride at full speed, where the hamstring is lengthening under load while the leg swings forward faster than any gym movement allows.

Which is why I get twitchy when a squad's injury plan consists of eccentric strength work and nothing else. It is good work. It is not the same work. If the tissue only ever meets its highest demand in competition, then competition is where it is being tested for the first time, and the first test is the one it fails.

The honest version of the argument is that the protective dose is exposure to speed itself, delivered often, in small amounts, all year. Not a block of sprint work bolted on in April. Short accelerations to near maximum, ten or fifteen seconds of it, twice a week, through the winter, so that the fast units are never strangers to the movement they will be asked to perform in a final.

The reason clubs do not do this is not ignorance. It is fear, and the fear is rational, because sprinting is when athletes get hurt and no coach wants to be the one who scheduled the session that ended a season. So the risk gets deferred. It does not get removed. It gets moved to a week when the athlete is less prepared for it and the stakes are higher.

There is a second reason, less flattering. Strength work is easy to measure and easy to show a director of performance. Reps, kilos, a chart that goes up. Exposure to near-maximum speed produces a number nobody wants to put in a report, because the number is the thing everyone is afraid of.

I would rather see that number than a squat total.