Aerobic exercise is overrated for weight loss

Editor’s Note: This is the first of a two-part series on the benefits of strength training. Part two will appear in the Beauty, Health & Fitness section of the Thursday, June 17 issue of the Sun Newspapers.

“I want to lose some weight and tone my body, but I only have so much time during the week to dedicate towards exercise.  I tend to do more cardio than weight lifting, but I am not seeing any results.  What should I do?”—Krista McCullough, Long Beach

Most of us over the past two decades have been told that doing “cardio” or “aerobics” workouts are the best way to lose weight.

I’m going to argue that this type of exercise is overrated as a tool for fat loss.

But before I do, let me point out that I’m not disputing any of the facts that are indisputable.

Does endurance exercise burn calories?

Sure.

Does it contribute to a longer, healthier life?

Absolutely.

I’m not out to demonize anyone’s favorite type of exercise. I just want to make the case that a comprehensive strength-training program gives you plenty of exercise, including exercise at high levels of intensity, and thus delivering all the benefits you want from endurance exercise without requiring very much of it.

“Aerobics” is a made-up word, coined by Dr. Kenneth Cooper, a former college track star, to promote steady-pace exercise in the 1960s.

Cooper believed that endurance training was the key to everything. It was a counterintuitive idea that gained a permanent foothold in science and practice.

I call it “counterintuitive” because the human species isn’t really designed for long-distance runs. By nature we are not good at jogging or swimming at a steady pace for longer than a few minutes despite what other professionals have said for decades.  We evolved to walk long distances and to run really fast when we must.

We’re good at start-stop activities involving lots of different speeds and changes of direction, which is why human children instinctively play games like “tag,” why human adults invent games like basketball and soccer, and why fighting sports like boxing and tae kwon do have rounds of several minutes, rather than continuous action until one fighter wins.

Let’s slow down for a moment, and ask why strength training has a bigger effect on metabolism and post-exercise fat-burn than endurance exercise.

Inefficiency is ideal

It is our body’s job to be efficient.  Our body survives from one of the basic principles of energy conservation; use the least amount of energy for any particular movement or activity.

Being efficient is also known as hitting a plateau.  When trying to achieve results like burning fat you want to be inefficient as much as possible.

Inefficient exercise routines require more effort because your body hasn’t fully adapted to the exercise parameters and thus has to work harder to get through the routine.

Harder work means better results—you’ll burn more calories during the workout, and you’ll burn more afterwards, when your body is recovering. In other words, inefficiency is ideal.

Your body adapts

The problem with a repetitive routine, like running or cycling, is that your body makes adaptations and gets progressively more efficient.

Those adaptations allow you to go farther and faster in your runs or rides, which is good if your goal is to be an endurance athlete who goes farther and faster.

If your goal is to be leaner, then greater endurance isn’t really to your benefit; the increased efficiency means you use fewer calories per unit of exercise.

To be fair, it’s hard to make the argument that our species evolved to do sets of bench presses or dead lifts, either.

So maybe it’s facetious to take any aspect of modern life, including our exercise routines, and put them into a prehistoric context.

I’m just trying to make the point that the ability to do anaerobic exercises—lifting heavy things, running fast, jumping, climbing, fighting—was vital to the survival of our species (primal movement patterns). Being able to jog for an hour at a specified percentage of your maximum heart rate wasn’t vital for our survival.

Burning fat

The word “aerobic” refers to the aerobic energy system, one of three ways your body can fuel movement.

You use your aerobic system constantly, whether you think about it or not. As long as you’re breathing easily, whether you’re working, sleeping, doing chores, or exercising, you’re using it.

That is, you’re using oxygen to burn a combination of fat and glycogen to keep your body functioning.

Generally, the healthier you are, the higher the percentage of fat you’ll burn at rest.

If you’re obese and/or diabetic, you’ll burn more glycogen and less fat.

During exercise, as your heart rate quickens and you start breathing harder, the ratio for burning fat potentially decreases depending on the time and intensity of exercise.

All-out exercise is anaerobic—your body can’t use oxygen to burn fuel, so it uses chemicals inside your body to generate the energy it needs. When your body needs to fuel movement without oxygen, it uses glycogen, rather than fat, to keep you moving.

The amount of fat you burn during exercise matters less than the amount you burn when you aren’t exercising.

And that’s where you start to see some of the hidden benefits of strength training.  If you compare the number of calories burned during endurance exercise to the number burned during strength training, endurance wins pretty easily.

It is easy to see why strength training doesn’t slay calories the way endurance exercise does. You spend more time resting in between sets than you do actually lifting, and you certainly aren’t burning fat while you’re pushing and pulling weights.

However, the appearance of losing weight through endurance exercise is misleading, as I’ll explain in the June 17 issue of the Sun Newspapers.

Bryce Turner is the co-owner of Beach Fitness at 148 Main E and F. He has a bachelor’s degree in physical therapy/exercise science and welcomes your questions on fitness.   Do you have a question for Bryce and this column? Call him at (562) 493-8426 or e-mail him at bryce@beachfitness.com.