When I've been on the treadmill or hiking, I've gotten this intense pain on my lower calves and ankle. If I'm on the elliptical, stairmaster, bike, whatever, I don't have it, but once I hop on the treadmill or do some hiking (normal walking is fine), it feels like my muscles are being stretched and that they're going to break at any point. It is really painful and it feels different from normal workout burn. Is that something to be concerned about or is it just part of working out? it's really holding up my workouts. I've also started stretching more, but maybe I'm not stretching enough or correctly? Anyone have some ideas on how to alleviate this?