Today, I felt like trying a pistol on each leg. I elevated my heels, and did one left first. I stalled about halfway up, but finished. Right leg I became unbalanced when I first began to come up, and used my hands to push up a little bit. My left leg felt strained again during this (I have no idea?).
I did these with no warmup, and in hindsight I am a dumbass for doing so... My quad felt fine afterwards, so I did 3x5 of back squat at an easy 95lbs.
I've been hand massaging/foam rolling, as well as stretching.
Any other ideas/suggestions?