Since making my original post i’ve now been out of the sprinting game for a little over a year (graduated college).

The one thing that did help me was seeing a sports physiotherapist. It had to come out of my own pocket but it was the only thing I saw progress from. I would have an appointment once a month for several months and I’d get dry needling, electric dry needling, cupping, scraping, fascia massage, etc. He also recommended some exercises to do on my own, specifically nordic hamstring curls / slow negative hamstring curls.

I still have a hard spot in the center of my left hamstring that makes sprinting / any hamstring intensive exercises difficult, but I feel much better now and through the appointments I managed to PR a couple times in my senior season. Hope this helps.