Thursday night, a "core" class, we ended by doing 110 lunges--step forward, bend the front knee, let the other knee almost touch the floor. Sensei said we would hurt the next day. Friday, I felt okay. But at 12:20 Saturday morning, in bed, I got the most intense cramp in my right hamstring. Ouch.
Class today, Saturday, another core class, was very difficult for me. I'm still worried about hurting my ACL and knee, so my round kicks aren't very pretty. And I was tired from the first push-ups in class. I think maybe I didn't get enough sleep this week.