"Lee's Secret!!" (リーの秘密!!, Rī no Himitsu!!) is chapter 82 of the original Naruto manga.
Lee attacks Gaara. By manipulating the sand he keeps stored in the gourd on his back, Gaara is able to block all of Lee's attacks. Seeing that Lee will not get anywhere as he currently is, Guy tells Lee to "take them off". Lee complies, removing his ankle weights. The observers doubt the likelihood that their removal will make much of a difference, but find that, when dropped, the weights create large craters in the ground. Lee's speed is greatly increased, allowing him to attack Gaara before his defences have a chance to respond.