200 skipping ropes consume 30 calories, and 400 skipping ropes consume 40 calories because 400 skipping ropes are fast jumps. The energy consumed by skipping rope is related to the speed of skipping rope. In the same situation, the fast pace consumes less energy, and everything has an adaptation process. Relatively speaking, the less energy is consumed later. So 200 non-stop skipping ropes consume 30 cards, and 400 skipping ropes consume 40 cards.