The musculoskeletal system is the body’s largest user of energy. It is through the this system that we walk, talk, run, jump, feed ourselves, paint pictures, perform delicate surgery, make music, war and love,...
For aerobic exercise, you can divide efforts into three basic zones on the basis of how your body reacts. The easiest is the aerobic zone, where your heart and lungs are able to deliver enough oxygen to your muscles to keep them functioning. In contrast, the hardest, or anaerobic, zone is where your muscles can’t get enough oxygen
Aerobic fitness is often assessed by measuring how much oxygen you can breathe in and deliver to your muscles when working as hard as you can, a quantity known as VO2max. You can improve aerobic fitness by doing activities that continuously use large muscle groups—walking, running, biking, step aerobics, swimming, dancing, and so on. These activities are sometimes lumped together as “cardio” exercises because they improve the health of your cardiorespiratory system—your heart and lungs.