I took a week off from riding and today decided to go for a 24-mile ride ...or so I thought. About 3 miles into it, my left hamstring started cramping up while going uphill (not steep at all). After about a minute, it got so bad that I had to get off the bike and take a break. When I got back on, I took it really easy but kept going. After a while my right hamstring cramped up. I only rode 12 miles before calling it quits. I'm home now and my hamstrings are still hurting every time I get off the couch. I went from riding 200-250 miles a week to basically doing nothing in the last 6 days (there was a good reason). What happened to me?