Not sure if this is relevant, but it costs me nothing to post, and you don’t seem to be flooded with responses, so…
I’ve recently read some articles that discuss how the hamstring tendons cope with stored (“elastic”) energy, and how they can be damaged during intense exercises - it doesn’t have to be all-out sprints (or similar high range-of-motion exercises), anything intense and unusual can be enough, even if you think you’re going fairly easily.
Like you, I also get a similar pain, but in my case, it’s after sprinting (no issues with good mornings, and funnily enough, I did 10 sets of three yesterday as part of a Waterbury workout). In my case, the hamstring deep in the top right leg starts to stiffen up over several hours after a sprinting session, and it becomes quite uncomfortable for several days (and I lose some ROM).
I’ve tried all kinds of warm-ups (focusing on dynamic moves), but haven’t successfully addressed this thus far. I’ve also tried Chiro and accupuncture - no effect at all.
Yesterday, I experimented whilst doing my sled-pulls - I tried “sprinting” whilst pulling about 100LB behind me. Obviously I was much slower than when I run, and the range of motion was very limited by comparison, but the “intensity” was high, so the elastic energy element should also have been very high. Interestingly, I managed to recreate the sensation in my right ham that I can get when I sprint (I stopped as soon as I noticed this). This was the first time I’ve recreated the effect outside “sprints”, and it is in-line with my recent readings - i.e. they effectively predict it would occur, because it’s not related to range of motion issues (as I once thought), as much as it is the inability of the tendon to cope with the “elastic energy” load during intense effort. I am actually encouraged by this finding as I can try their preventative suggestions, as an experiment, to see if it addresses the problems.
The article suggests static stretches in between sets (in my case, 400m sprints). These are in addition to dynamic stretches etc. The static stretches during an exercise are supposed to help make the tendons more able to cope with the stress of elastic energy during intense work (sprints, in my case). I have no idea if it works, but if I keep to my schedule, I’ll know tomorrow morning sometime after 6:00AM…
I share this with you because your issue sounds as though it’s similar to mine. I caution you though: the article I read could be wrong, I may be on the wrong track, or this might make matters worse (for me as well as you), so take a pinch of salt and fire up your search engine and see what else you can find - I have spent hours researching and reading (and probably getting dumber!).
One thing I have learned is that hamstring injuries can be really bad in terms of time to heal (or inability to fully heal), so if you experiment - take it easy and stop at the first sign of issues.
That being said, I’m buggered if I’m going to give up sprints without at least trying some ways to address this. It’s easy to quit, it’s more challenging to find a way through this.
I have the articles printed somewhere, but can’t easily find them right now. Let me know if you think this is worth a read and I’ll do some digging and post a link.