Special straps for strength training.

[Bones]

I had a friend who had these special velcro belt things which he'd got off a pro rugby player mate in Japan. I think they were called Katsu or something like that.<br />
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Anyone heard of them? They were basically straps which you could do up tight around the top of your thighs/arms, etc, and then do exercises to basically isolate the muscle and make it work harder I guess (with less oxygen?).<br />
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I'd be interested to know if anyone's used them or knows how to get them - even what they are called!