Do these actually do anything? I mean I do them, but I'm not really sure what purpose they serve. I would imagine you wouldn't gain any mass with them. But maybe improve your strength slightly? I don't know. I've never relied on them alone and always did other things to work my legs so it's hard to tell how effective they are. Your thoughts?
Good for building up the endurance in your legs. Your muscles are activated for an extended period of time.
