(1) When exercising the muscle strength of the arm, the A end of the rope is fixed, and the hand pulls the rope at the B position to make the weight G rise.

At this time, pulley O moves with the weight, and pulley O is a moving pulley. As can be seen from the figure, the hand pulling force is at least: f = 2g = 2mg = 2× 30kg×10n/kg = 600n.

(2) When exercising leg muscle strength, the end of the rope B is fixed, and the leg pulls the rope at the position A to make the weight G rise. At this time, pulley O is fixed, and pulley O is the crown block.

The leg tension is at least: f = g = mg = 30kg× 10n/kg = 300n.

So the answer is: (1) move; 600; (2) setting; 300.