Calf Strain while POSE running
I've been doing Crossfit for about 3 months and started working on POSE running about 6 weeks ago after watching a couple of videos on it. I've never been formally trained in running, and have always struggled with it. I ran the 5K the last time it came up as a WOD using POSE and actually finished it and felt good afterward.
Yesterday I decided to do a little running on the treadmill. I walked a quarter mile, then ran a quarter, then walked a little and ran another quarter. On my fourth quarter mile run, I felt my right calf tighten up so I stopped. It's sore today and tight, but not as bad as I thought it would be. I've never strained a calf muscle running. I've never strained my right calf muscle in my life.
What could have caused the strain? Obviously the running, but why now and never before? A little more info: I'm 38, I strained my right Achilles a few years ago, & I was running barefoot. Any thoughts or comments?