Wednesday, November 12, 2008

Fat Burning Zone vs. Cardio Training Zone

A common misconception that I often have to explain and clarify relates to the aspect of cardiovascular training - “fat burning” (low-intensity) workouts result in better fat loss results than “cardio training” (high-intensity) workouts. Nothing could be further (or misleading for that matter) from the truth. Let's take a closer look at some of the important aspects of fat loss that you may already be implementing, and some that you are most likely not using. These could make all the difference in burning off those final pounds and giving you the lean, defined physique and six pack abs that you've been working so hard to get.

Resting State
At rest, the body burns a mix of fuels that come in the form of stored body fat (fatty acids) and stored sugar found in the muscles (glucose). Since our bodies don’t like to burn proteins for energy, we are left with carbohydrates (another fancy name for ‘sugar’) and fat. Given that we’re in the resting state, the “average” person will burn about 70% fat and 30% of carbs for energy.

Progression from Rest to Exercise (Physical Activity)
As a person moves from rest to activity, the percentage of fuel coming from fat will decrease and the percentage from carbs will increase. What this means is that as we move faster and harder, we are using less body fat for energy and more stored sugar. The more intense the exercise, the more carbs and less fat in the mix. What if my goal is to lose fat? Why would I want to move faster & harder knowing that I’m burning less fat? Here’s your answer.

Fat Burn Zone Myth Debunked
Many people assume that in order to “burn fat” they need to exercise at lower intensities, also known as the “fat burning zone”. However, this is where most people “miss the boat”, so to say. Going back to the resting state as mentioned earlier, although a greater percentage of calories from fat are burned as a person exercises at low intensity levels, you’re ultimately burning a lower total amount of calories from fat. On the flip side, at higher intensity exercise, the percentage of calories from fat goes down but the overall total calories burned from fat are greater. The ultimate goal for fat loss should rely on the total calories burned, not the percentage burned.

Still confused? Let me give you an example of how this works:


Let’s say two friends, Adam & Bill, decide to go for a cardio workout. Adam is exercising at a fairly low intensity (fat burning zone) that burns about 100 calories/hour. Let’s assume that 70% of those calories are coming from fat.

Bill, on the other hand, is exercising at a higher intensity (cardio training zone) that burns about 300 calories/hour. Only 50% of those calories are coming from fat.

Let’s do the math and get the results for Adam & Bill.
Adam is burning a higher percentage of fat, but 70% of 100 calories results in 70 fat calories burned.

Bill is burning a lower percentage of fat, but 50% of 300 calories results in 150 fat calories burned.

Bill burned twice as much fat calories than Adam did by working at a higher intensity at the same time period. This why the cardio training zone burns more fat overall than the so-called 'fat burning zone'.


No comments: