In reply to peebles boy:
I use them for trail and fell running and ski touring. In both cases my own perception is that they do not confer any advantage during activity (all the manufacturers would claim that they do) but they improve my recovery, DOMS in particular, quite considerably. It is possible that this is placebo effect but I'm happy to cash in on it without overanalysing. For ultra long runs they are great for preventing chaffing
P