The Fat Burning Zone Versus The Anaerobic Zone

When you decide to join the fitness revolution and get into shape it is important to be smart and educate yourself on all of the important aspects that make up an “efficient” workout regimen.

One aspect of efficient in this case can literally mean getting the best results in the least amount of workout time. This means being able to achieve optimal results in as little time as possible, because let’s face it we all have busy lives, and the number one excuse people make for not working out is they are short on time.

Therefore, understanding the science behind exercise becomes an essential element of success. The old saying, knowledge is power, applies in the world of fitness as much as, if not more, as anywhere else.

The world of fitness is placated with controversy on a daily basis. What one expert swears by, another expert will tell you is complete bunk. The fabled “fat burning zone” ranks high on this list of mysticism. It doesn’t really matter what the “experts” say. You can’t fix stupid and you can’t deny common sense.

Let’s take a little deeper look into the fat burning zone and compare it to the anaerobic zone.

The Fat Burning Zone

From a physiological perspective, it’s a little more complicated than it looks. You don’t simply JUST burn fat when your heart rate is at a certain level and magically lose weight. In reality, your body is always burning some form of substrate for energy at all hours of the day. What makes a difference is the intensity you are working at.

In periods of low to moderate work, for example, you are predominately using oxygen and stored fat for energy, and little stored carbohydrates. That doesn’t mean you are just burning fat. It means you are MOSTLY burning fat and less carbs.

Now, as you increase your intensity, the ratio of fat burning to carb burning starts to change. It works on a continuum. The higher your intensity becomes, the less fat you will be burning and the more stored carbs you’ll burn. Common logic farmed us to believe that we wanted to stay in the fat burning, or aerobic, zone to yield the best weight loss results, but that is outdated thinking.

Sure, you might burn a decent amount of calories in two hours, trudging along on elliptical machine, but what do you think will happen when you are done working out? The simple answer is not much.

This is because you had a plentiful supply of oxygen during your workout and stayed in your happy little aerobic zone.

The Anaerobic State

Let’s reverse the tables now. Instead of doing the slow-mo workout, you instead press your foot on the accelerator and turn your intensity up so high that you can only maintain your pace for 30 to 45 seconds. You are out of breath and your legs start to burn.

You have now just crossed what’s called the anaerobic threshold where your body is burning little fat and predominately stored carbs for energy. And by the way, anaerobic literally means without oxygen.

Naturally, since you are working at a higher output, your caloric expenditure will reflect this. And that’s only the tip of the iceberg. When you get into that really high intensity level, something magical happens when you finish. Not only does your metabolism stay revved up for a day and a half, but you also get a high natural release of growth hormone and testosterone.

That’s why people who do sprints and circuit-style workouts are so lean and chiseled. They take short rest breaks, keep their heart rates elevated and enjoy the benefits that appear on their bodies.

How To Reach The Anaerobic State

For the best metabolic effect, you need to get in the anaerobic zone for four total minutes. It is hard to go more than 60 seconds at an all-out intensity, so it’s better to do it in an interval format. You are best served with 15-second bursts when just starting out, then gradually increase your time as you get in better shape.
Simply start with a light warmup, do intervals until you’ve achieved four minutes at the high intensity mark and finish with a light cooldown.

In the big picture, there is nothing wrong with aerobic exercise, but it’s not the say-all, do-all method for fat loss. If you are looking for fast results, just know that crossing the anaerobic threshold is going to be your best option.