But most people don't engage in cardiovascular exercises to improve their health or reduce their risk for cardiovascular diseases.
Most people want to lose weight.
Indeed, aerobic exercise is one of the best forms of exercise to burn calories. And burning excess calories is what will help you reduce your body fat.
However, not all cardiovascular exercise is created equal.
Recently, there was an article in a popular fitness magazine which posed a very interesting and important question: Which burns more calories? Running 1 mile, jogging 1 mile, or walking 1 mile?
The answer was that it was a trick question because it's the same distance, so all three activities burn the same amount of calories.
This is false. It just goes to show how much misinformation is out there.
I can empathize with the author because the notion is almost reasonable. It follows the logic of the classic riddle, "Which weighs more, a pound of steel or a pound of feathers?" The answer being of course, that a pound is a pound- so both weigh the same.
However, with cardiovascular exercise, it's not as simple as 'a mile is a mile'.
This is important to understand because many people are under the impression that if they just walk the same distance, they'll burn the same amount of calories as when jogging or running. Then they become disappointed when the scale fails to meet their expectations.
The rate of oxygen consumption or VO2, is a measure of an individual’s ability to take in and use oxygen. VO2max, a term many of you are familiar with, is just the highest rate of oxygen transport and use your body can achieve at maximal physical exertion.
When we breathe it in, oxygen is transported in the blood and carried to the tissues where it is involved in chemical reactions to produce adenosine triphosphate (ATP), the energy molecule which serves to fuel muscular contractions.
So when you exercise, your heart beats faster to deliver more oxygen to meet the energy demands of your activity. The harder you work, the more energy you burn.
Therefore, running at faster speeds increases oxygen consumption (VO2) and thus, expends more calories than jogging or walking.
Although different sources differ slightly, on average, a 150 lb person will burn:
-4.2 kcal·min walking at 3 mph -10 kcal·min speed walking at 5 mph -15 kcal·min jogging at 6 mph -16.1 kcal·min running at 8 mph
Hence, if a 150 lb person walks at 3 mph, it will take 20 minutes to complete a 1 mile distance. At 4.2 kcal·min., this person will burn a total of 84 calories:
-4.2 kcal·min x 20 min = 84 kcal
On the other hand, running the mile at 8 mph will take about 7 and a half minutes to complete. At roughly 16.1 kcal·min., this person will burn a total of 120.8 calories:
-16.1 kcal·min x 7.5 min = 120.8 kcal
Not only will it take 7 and a half minutes instead of 20 to complete the same 1 mile distance, but in this example, running will burn almost one and a half times more calories than walking.
The take home lesson here is that if you're interested in cardiovascular exercise to burn excess calories for body fat reduction, then remember that any activity requiring greater force production performed at higher intensities will always result in greater energy expenditure.
