That's been my general anecdotal experience. I found that wearing them during a run did nothing more than help keep my lower legs warm during a winter run. However, as one who's plagued by calf and achilles tightness and problems, keeping them on for the 30 minutes or so after the run, however, felt great and seemed to aid recovery of lower leg muscles. However, when it's hot and you get all sweaty, you feel like a gross pig sitting around wearing those things for a while after you run.
That's my experience. Take it for what it's worth.