What Part of the Body Do Cardio Exercises Affect?

Cardio exercise, also known as aerobic exercise, affects your muscles, bones, circulatory system, respiratory system and brain. Although sometimes cardio exercise can cause injury, the overall benefits of cardio activity to your body are so widespread that doctors call it the best way to improve your overall health and mental state. Cardio exercise will reduce your fat stores and helps fight off many types of illness, from heart disease and diabetes to cancer.

Types of Cardio Exercise

Cardio exercises are activities that make you breathe harder as your heart and lungs work to deliver more oxygen to the large muscle groups you are using. Cardio exercises include running, which uses your legs, and swimming, which primarily uses your arms, shoulders and back muscles. One of the best cardio exercises is cross-country skiing, which utilizes your legs and arms while strengthening your heart and lungs. During these and other cardio exercises, your small blood vessels widen to deliver oxygen to working muscles and to carry away carbon dioxide and lactic acid.

Many Benefits

Cardio exercise stimulates your immune system, making you less susceptible to viral infections such as colds. The Centers for Disease Control and Prevention reports that cardio exercises also have a positive impact on your mind by sharpening your thinking processes. According to the Mayo Clinic, cardio exercise affects your brain by reducing stress, depression, anxiety and tension. Immediately after exercising, your body often releases endorphins, natural pain-reducing substances that can give you a sense of well-being.

Effect on Your Arteries

The effect of exercise on your heart is often demonstrated by your resting heart rate. After several weeks of cardio exercise, you will notice that your pulse rate first thing in the morning – before you’ve gotten up or had that first cup of coffee – will be slower. This is a sign that your heart muscle is stronger and capable of delivering blood to the rest of your body at a slower rate. Cardio exercise also increases your high-density lipoprotein – the "good" cholesterol – and reduces low-density lipoprotein -- the "bad" cholesterol -- helping keep plaque from clogging your arteries.

Metabolic Rate

There are also benefits to the body’s respiratory system as your lungs become better at taking in oxygen for use by your muscles. Those muscles become firmer, and muscle enzymes become better at working at a low intensity for an increasing duration of exercise. Your metabolic rate – the pace at which you are burning calories – is also affected by cardio exercise, as it becomes elevated during your workout and remains elevated for a time afterward.

Burning Fat

Cardio exercise burns fat, and this can reduce your total body fat, which is stored under the skin, around internal organs and between muscle cells. When you exercise, you will at first burn glycogen for energy, but after 30 minutes the body will switch to burning fat. A pound of fat contains about 3,500 calories, so it takes regular and prolonged cardio exercise to have an effect on your body composition. If you diet to lose weight, adding exercise will keep your body from getting flabby as you reduce.