Your hamstring keeps going again.
The 3 things that actually change it.

01

Three things it probably is not.

It is probably not tight. That is the first thing worth putting down. A hamstring that feels tight when it is irritable is usually not short. It is holding on, because it does not trust the position. Stretching it buys you twenty minutes of relief and changes nothing about what the leg can handle. If you have stretched it every morning for six months and the sprint still goes, you already have your answer.

It is probably not waiting for more rest. Rest calms it down. It does not build it back up. Those are two different jobs and only one of them is the job you need doing.

And it is not sorted just because it stopped hurting. The pain leaves long before the strength does. That gap, between feeling fine and being ready, is where a lot of these go again. A scan can read almost clear while the leg is nowhere near ready for what you are about to ask of it. So if you have wondered whether you are making too much of this, whether everyone else just trains through it, whether this is simply your leg now, you are not imagining it. You are in the gap.

02

What is actually going on.

Your hamstring is being asked for more than it can currently handle, and it has become sensitive to being asked. Sensitive is not damaged. It means the leg has become protective, and the level it protects at now sits somewhere below your normal training.

It tends to show up in one of two ways. One is the strain. It went suddenly, at speed or with the leg stretched out in front of you, and it has never been quite right since. The other is the ache at the sitting bone. Deep in the back of the thigh, worse in the car, worse on hills, worse the longer you sit still. That one is a pressure problem as much as a load problem, because bending at the hip presses the tendon against the bone you sit on. Different tissue, different rules. Same story underneath.

Either way, resting it lowers what you ask of the leg. It never raises what the leg can give you. So the gap is exactly where you left it when you go back, and the first proper sprint walks straight into it.

03

What actually works.

Load it, and keep loading it past the point it feels fine. A hamstring that keeps going has lost its tolerance for two things: speed, and being stretched out long while it is working. Those are the two things a sprint asks for, and they are the two things that get avoided in rehab. What gives that tolerance back is being asked for both, in a dose the leg can take, with the dose climbing. Strength work that never gets fast and never gets long will not prepare a leg for a sprint. It prepares a leg for more strength work.

Match the plan to the pattern. If it is the strain, the work builds towards speed and towards length, and it earns each step before it takes the next one. If it is the ache at the sitting bone, the early work does close to the opposite of what most people try. Less deep hip bend, not more. Less stretching, not more. Stretching that one hard tends to keep it going, which is often why it has not settled.

Then let the next morning tell you. Back to how it felt before the session means the dose was right. Worse the next day means ease back a step. It does not mean you have done damage, and it does not mean you have set yourself back. It means the dose was a little too much, and the next one should be a little less.

04

What tends to disappoint.

Stretching harder. It is the first thing almost everyone reaches for and it is the thing that most reliably keeps this going, especially the sitting bone version. It feels productive. It changes nothing you need changed.

Testing it. You go out and do one sprint to see if it is better. It grumbles. You back off for a week. Then you test it again. That is not rehab, it is a fortnightly flare with a rest in the middle.

Stopping in the boring middle. It feels fine at three quarter pace, so the work quietly stops. But three quarter pace was never what did it. The leg goes at full speed, at full stretch. If it has never met that in rehab, it meets it for the first time in a game.

05

What getting it right looks like.

Four stages, in order. Settle it enough to walk and move without it flaring. Rebuild strength through the range you have got. Restore what speed and length actually demand, which is the stage nearly everybody skips. Then return towards your sport in graded steps, rather than in one leap on a Saturday morning.

Progress runs on how it responds, not on the calendar. Nobody can honestly tell you it is six weeks. The leg tells you, session by session.

If it flares, you drop back to the last level that felt fine. You do not start again. That distinction is worth more than any exercise on the list.

And the riskiest moment is not the injury. It is the first few weeks back, when it feels good and you have started to trust it again. That is when these go for the second time. The plan should still be running then, not filed away.

Some things are worth getting looked at before anything gets loaded. A sudden pop with the leg going forwards, heavy bruising, and a leg that will not take your weight. A leg that is swollen, warm or red. Pins and needles, numbness or weakness running down it. A lump. Pain at night, or pain that carries on regardless of what you did that day. And any teenager with pain at the sitting bone, because a still growing pelvis needs checking before it gets loaded. None of that is a reason to panic. It is a reason to get assessed properly before anyone hands you a plan.