Hamstrings: when strong isn’t enough

If you've strained a hamstring or been diagnosed with a tendinopathy, sprinting probably feels like the enemy — it's often what caused the injury, or it's the exact movement that reproduces your pain. So it can be surprising when it is recommended to do controlled sprint work before you're "fully healed."

Here's why that's not a mistake, and what the research actually supports.

The core idea

Muscles and tendons don't just contract — they also work like springs, storing energy and releasing it to propel you forward. Sprinting is the movement that demands the most of that spring-like function. Strength training alone (slow squats, bridges, even heavy resistance work) builds tissue capacity, but it doesn't teach the hamstring or tendon to handle high-speed, energy-storing loading. If rehab stops before that stage, you're sending someone back to sport with a gap between what they trained and what their sport actually demands.

Evidence-backed recommendations

1. Treat return-to-sprint as a planned phase of rehab, not the finish line. Research on hamstring strain recovery consistently identifies high-speed running as one of the most important elements of rehabilitation, since it's fundamental to performance in most sports. A widely referenced framework (Hickey et al., 2022) lays out a structured, three-stage running progression that's built into rehab from early on, rather than something attempted only once a patient feels "ready."

2. Pair sprint-speed running with strength in the lengthened hamstring position. Athletes recovering from a hamstring strain tend to be weakest specifically when the hamstring is in a lengthened position — the position it's in during late swing phase of sprinting, where many strains occur. Exercises like Nordic curls, run alongside a running progression, address this directly rather than relying on running exposure alone.

3. Don't treat sprinting purely as a risk factor to avoid. A recent scoping review on sprint training and hamstring injury found that controlled, progressive high-speed running may play a protective role against reinjury, not just a provocative one — likely because it's the only way to build genuine tolerance for the forces sprinting produces. Avoiding sprinting doesn't remove that demand; it just postpones it to a less controlled setting, like a game.

4. Introduce technical sprint work earlier rather than saving it for the very end. A comparative study of track and field athletes found that those who had structured, technical sprint drills built into early rehab returned to full participation faster and had fewer reinjuries than those who did high-volume, low-intensity work first and added sprinting only at the end.

5. For tendinopathy, treat energy-storage loading (hopping, jumping, sprinting) as its own required stage — not optional. The accepted rehab progression for tendinopathy (proximal hamstring, Achilles, patellar) moves through isometric holds, then heavier strength work, and finally energy-storage loading. A tendon that's been strengthened through heavy, slow resistance training but never exposed to spring-like loading isn't actually prepared for running or sport — and skipping this stage is identified in the literature as one of the most common reasons tendinopathy symptoms return after someone resumes their sport.

6. Progress tendon-specific case evidence supports the same staged approach. Case-based research on proximal hamstring tendinopathy applying an isometric → progressive strengthening → energy-storage progression has shown good outcomes, including measurable improvement in tendon tissue quality on follow-up imaging.

The takeaway

Sprinting is a real load, and reintroducing it carelessly is how reinjuries happen. But never reintroducing it — or waiting for zero pain before trying it — leaves the hamstring or tendon undertrained for the one demand it will eventually face again anyway. That's why we build sprinting into your program deliberately, in small controlled doses layered on top of your strength work, rather than treating it as the last box to check before you're "cleared."

References

• Hickey JT, Opar DA, Weiss LJ, Heiderscheit BC. Hamstring Strain Injury Rehabilitation. J Athl Train. 2022;57(2):125-135.

• Sprint Training for Hamstring Injury Prevention: A Scoping Review. Applied Sciences. 2025;15(16):9003.

• Technical Sprinting in the Early Phase of Hamstring Injury Rehabilitation to Accelerate Return to Full Participation in Track and Field Athletes. Int J Sports Phys Ther (PMC), 2024.

• Clinical Progression and Load Management For Proximal Hamstring Tendinopathy In A Long-Distance Runner: A Case Report. Int J Sports Phys Ther.

• Loading For Tendinopathies: The Complete Guide (energy-storage/plyometric staging in tendon rehab).

• Tendinopathy Rehabilitation. Physiopedia.