ALL FIT: Episode 7 CARDIO RESPIRATORY FITNESS Slim tells viewers how the heart, lungs, blood, and blood vessels work together to make us fit and healthy. Slim explains that the h... more »eart beats at different rates depending on how hard the body is working. Slim meets Slenda and the All Fit Team at Slim's Gym where Slenda leads a vigorous exercise session then demonstrates how to feel your own pulse. In the Body Lab, Slim shows viewers an inside look at their heart and demonstrates how the cardiac muscle works. He explains that aerobic exercise provides muscles with a steady flow of oxygen to keep them working efficiently. Slim teaches the name and location of the cardiac muscle.« less