Today was my optional day; I chose to do some weights, core, and a bit of stretching.
My legs (esp. my left leg) are quite sore from yesterday. I believe it's my hamstrings, but it's all the way at the top where they attach. I did some one-legged squats and some step-ups and walking lunges, and only the walking lunges used the muscles that are hurting. Sigh. Still not using my glutes correctly, I'm sure.
Hopefully I'll be recovered enough for tomorrow's 10K fartlek. This week is a tough one!