I’m a physical therapist. This is why stretching your tight hamstrings might actually be making the problem worse

Here's why your obsession with stretching is actually keeping you tight and how to finally find relief.
BMJ

Hamstring force and stretch during progressively increasing running speeds and the eccentric phase of resistance training exercises commonly used for injury prevention and ...

Objectives To compare the force and stretch demands experienced by the hamstrings during seven resistance training rehabilitation exercises and progressively increasing running speeds. Methods A cross ...