DB Chapter 177
From Dragon Ball Encyclopedia, the ''Dragon Ball'' wiki
"Goku vs. Tenshinhan, Part 2" (スピード, Supīdo; Literally meaning "Speed") is chapter 177 of the Dragon Ball manga.
Tenshinhan is impressed with Son's progress, but says he'll win this match with speed. He comes at Goku, and vanishes, and then Goku vanishes as well. They're up in the air, and Goku is frantically kicking at Tenshinhan. Tenshinhan then comes back into view, and compliments Goku's eyes, and asks what happens when he can't see him with his eyes. Tenshinhan then gets above Goku and elbows him down toward the ring.
Goku lands safely, and flips backwards, elbowing a Tenshinhan afterimage. Goku prepares to move again, but then Tenshinhan comes back into view and kicks Goku out of the ring. But Goku spins like a tornado back into the ring, and he compliments Tenshinhan's speed. Tenshinhan says with his speed, he's sure to win, and Goku asks for a minute to change his clothes.
Goku pulls down his top, and then takes off his undershirt and throws it to the ground, with a big thud. Tenshinhan picks up his shirt, and sees that it's really heavy. Goku explains that the weighted clothing was part of God's training. Even with Kame-Sen'nin he wore heavy turtle shells. Tenshinhan then sees his shoes and wrist guards were all heavy, too.
Kuririn and Yamcha come in the ring to take Goku's shoes and stuff backstage, and freak out when they notice how heavy they are. Tenshinhan says altogether that stuff's more than a hundred kilograms, and the announcer and the audience freak out. Goku then jumps up and down, feeling light now, and so they'll get back to the fight. Tenshinhan rushes at Goku, and Goku vanishes, but then Tenshinhan spots him and comes at him with an elbow, but Goku blocks it. They stop, and Tenshinhan thinks Goku's speed wasn't much after all. But then Goku shows he has Tenshinhan's obi (sash thing he wears around his waist), and Tenshinhan's pants fall down.