“Don’t mistake movement for achievement!” my college basketball coach used to yell at my team as we cut and moved around the court out of habit or ploys to look busy.

I had no idea what he was talking about until years later: Just because we were moving did not mean that we were applying the intensity that would create a result.

We can apply this warning from my old sage of a coach to the way that most people exercise today: Lots of movement. Limited results.

Trendy fitness chains crank the music, the room temperature and the clichés. Students pour sweat under the belief that it is achieving weight loss and other results.

It is not.

I can sit in a sauna and sweat my butt off, but that does not mean that I am burning calories.

If I want results, I have to earn them.

If this sounds difficult, that is because it is.

But it is also liberating. Because the harder I work, the faster I can transform and the faster my workouts can be.

All exercise is not created equally, especially when it comes to burning calories efficiently. This is because our intensity level determines which of our body’s three energy systems – oxidative, glycolytic or ATP-PC – is powering our workouts.

Low-intensity exercise relies on the same system that we use at rest: the oxidative system, which predominantly uses oxygen as energy. Consuming oxygen burns calories. But this intensity level does not elevate our oxygen intake much from our resting state, so exercising in this system is not the most efficient at burning calories.

Medium-intensity exercise compels the glycolytic system to take over as our oxygen intake fails to fuel our movements. This system pulls from the body’s stored energy, which prevents it from turning into fat. The oxidative system does this eventually, but this forces us to work out for longer.

Medium-intensity exercise is also more efficient at burning calories because it requires more oxygen. The stored energy covers for oxygen in the moment, but it does not replace the need for it. Repayment of this oxygen debt can take hours to achieve, enabling us to continue to burn calories after we work out.

High-intensity exercise triggers the ATP-PC system to release a more potent form of stored muscle energy – ATP – to jolt our bodies to exert maximum effort. This burns stored energy even faster than the other two systems do. The greater intensity also heightens the oxygen debt, propelling us to torch even more calories post-workout.

High Intensity Workout, Torching Calories, The Big Yogi

Because the ATP-PC and glycolytic systems can sustain our movements for only seconds or minutes, targeting them also guarantees shorter workouts. To increase the efficiency of our exercise, we must increase the intensity – not the duration, which invites the oxidative system to resume control.

Let’s compare the number of calories that exercising in each energy system can burn per hour to evaluate their efficiency. To determine caloric expenditure per hour of exercise, multiply the metabolic equivalents listed below by your body weight in kilograms. One MET is a calculation of energy cost based on the amount of oxygen that we consume at rest.

For example: 10 METS x 70 kilograms = about 700 kilocalories burned per hour.

Oxidative System

Intensity: low
Duration: long ( > 2 minutes)

Walking – 3
Cycling – 3
Aerobic dancing – 4

Glycolytic System

Intensity: medium
Duration: short (12 seconds to 2 minutes)

Basketball – 8
Jogging – 10
Jump-rope – 10

ATP-PC System

Intensity: high
Duration: short ( < 12 seconds)

Boxing – 12
Rowing – 13
Sprinting – 16

Notice that the number of calories that we burn does not depend on duration or even type of exercise. It all comes down to the effort and, therefore, oxygen that we consume and energy that we expend.

Why jog for an hour on a treadmill when we can burn more calories doing 10 all-out sprints? Because most exercisers go for what is easy. Easy sells because it gets us in the door and keeps us in our comfort zones.

The hard work that arouses the glycolytic and ATP-PC systems is not sexy. Overheated rooms and overused phrases do not manufacture the sweat. It springs from unvarnished and authentic effort.

It will not take much time to start training yourself in these two systems given the fire that they require. Start lightly and be cautious to avoid injury. I even suggest learning directly from a professional if training in these systems is new to you.

If you are tired of wasting time and never seeing the body or performance that you want, do not turn up the heat of the room or your workout schedule. Turn up the heat of your intensity. Earn your fitness and physique.

Are you ready to earn the benefits of efficient exercise? Come to one of our public group training sessions or sign up for our small-group personal training today!

A Maur Unity collaboration, edited by Maura Bogue