How important is intensity? I'm in my mid-40s, I’ve been running for a year, and I’m a big guy (6'3”, 240lbs). I run mainly to improve my health and I’m not out to break records. I am wondering if increasing intensity will increase injury risk. Thanks, DougIntensity, overall, is very important, as it is what guides you to purposeful running—whether you’re out for overall health or you’re looking to improve performance.