The term "cardio" is short for cardiovascular, referring to the heart and blood vessels. Just like the biceps and quads, the heart is a muscle too with the purpose of pushing blood through the body. The stronger one's heart, the more blood the heart is able to pump.

The benefits from a strong heart are great and quite noticeable. A great way to measure one's progress is to take your resting heart rate. This can be done by checking your pulse and counting the beats per minute. Just count how many beats for 20 seconds and multiply by 3, this should be close enough. Start your cardio program and 2 weeks down the road, check your pulse again and compare the beats per minute to the last time you took them. This should always be done once you have been resting for at least 30 minutes. The best time to take your pulse would be right when you wake up. Depending on your age, a fantastic goal to shoot for is a range of 60-70 beats per minute. Some marathon runners have been known to have resting heart rates in the 40's.

As one's cardiovascular shape increases, they will also notice their muscles and lungs burn less due to the increased efficiency of their heart. The reason for this is as the heart pumps more red blood (which contains the necessary oxygen carried by hemoglobin) to the cells that require the oxygen. These cells are then able to keep up with the demand you are placing on them by maintaining aerobic respiration as opposed to anaerobic respiration (without oxygen), which produces lactic acid, causing the muscles to become fatigued and burn.

Many individuals are turned off from focusing on cardio exercise programs because of the pain often associated with them. The great news is how the human body can adapt to such situations and as the heart grows stronger, the pain fades away. Coupling a strong cardio program with a variety of exercises can often yield fantastic results for those willing to put in the time and effort.

Activities that involve cardio based exercise include: bipedal locomotion, cycling, and swimming.

Here is a basic calorie burning list of activities (average calories burned per hour) :

  • Sleeping: 72
  • Sitting: 72-84
  • Walking (3.5mph): 336-420
  • Swimming (basic): 360
  • Cycling: 360-420
  • Jogging (5mph): 600
  • Running (7.5mph): 900
  • Running (10mph): 1200