Hamstring Injury...Why?

The pulled left hamstring was the worst injury I've had since December 2005. What happened?

The first hamstring pain on April 17th was completely out of the blue. I'd been dealing with some little niggles from my left knee and right Achilles tendon, but up until that Sunday afternoon I hadn't felt anything unusual from a hamstring. And then, Bam, less than two miles into a relatively easy run I had a sharp pain that convinced me to walk home. After a week of rest I tried running the next Sunday, but again before I'd run two miles, the sharp pain returned to the back of my left leg. I was frustrated enough to push the pain and run most of the way home. That stupid decision clearly led to a two and a half week layoff. But what happened to start the hamstring problem the week before?

I'd been running 50 to 60 miles a week through February and March, but a refueling outage at the nuke plant cut back training time so I was down to the mid-40s for the three weeks before the hamstring problem appeared. I was working on speeding up the Tuesday morning tempo-run. The run on April 5th was within a half second of my fastest Tuesday tempo of 2011 from early in March. April 12th was much warmer but the Tuesday tempo was only a little slower. I'd also added some strides, usually on Wednesday morning. I don't normally run strides, but I hadn't been doing any interval training and I was hoping the faster turnover during the strides would help in the shorter Spring races. I was doing four strides, after running two to four miles. The strides were gradual buildups over about 100 meters (I was just using street lights), accelerating up to a sprint and holding that pace for about 20 to 30 meters. At the time, I thought it was a conservative approach.

I never had any leg problems during the strides, but in retrospect they seem to be the most likely initiator of the hamstring injury. Strides are pretty traditional training, but next time I think I'll add 800s or 400s before I start running fast strides.