When you have limited time available to work out, you want to choose the most efficient and effective type of exercise to reach your goals, right? That’s where metabolic workouts—or metabolic training—come into play.

In this article, we'll cover:

• Your metabolism
• The basics of metabolic workouts
• Pros and cons of metabolic workouts
• The difference between metabolic workouts and HIIT 
• Metabolic workouts and blood sugar spikes
• A sample metabolic workout plan to get you started.

Your metabolism

Metabolism refers to all of the chemical reactions that occur in the body to maintain itself—like breathing, blood circulation, digesting food, growing and repairing cells, regulating body temperature and even managing hormone levels ¹. And metabolism is also the process of acquiring, transporting, using and disposing of nutrients in the body. Basically, this is how your body runs.

There is also a term called “exercise metabolism”, which refers to how energy is transformed through the physiological changes and demands placed on the body during exercise. This is how your body runs when you work out.

In order for the body to perform exercise (such as a bicep curl or a burpee or a long run), the body needs fuel, which it gets through food. Food is then converted into smaller and usable substrates, such as carbohydrates, proteins and fats (also known as macronutrients).

ATP

One molecule that’s very important to know in energy metabolism is called adenosine triphosphate or ATP. ATP is essentially a source for use and storage of energy in the body. When the bonds of ATP are broken, energy is transferred. And, in order to fuel your workouts and complete muscle contractions, you have to use ATP². 

The intensity of your workout will decide the rate of ATP production and consumption, and there are three main pathways in the body that can generate ATP, including:

1. The ATP-PC system (immediate energy) - used for high-intensity exercise 
2. The glycolytic system (short-term energy) - used for medium-intensity exercise
3. The oxidative or aerobic system (long-term energy) - used for low-intensity exercise

Depending on the intensity and length of your workout, you’ll be one of these ways of creating ATP in your body. The goal of metabolic workouts is to use the medium- and short-term energy pathways to get optimal results.

And now we’re ready to get into the basics of metabolic workouts.

What are metabolic workouts?

“To put it simply, metabolic conditioning workouts are periods of intense work alternated with periods of rest – either structured or unstructured,” says Paige Kumpf, ACE certified personal trainer.

Metabolic workouts (which can also be called metabolic conditioning or “MetCon”) are a way of working at a medium- to high-intensity to take advantage of immediate and after-exercise benefits, to boost your metabolism.

“These workouts will improve the conditioning of the cardiovascular system to be able to handle higher and more intense bouts of work with relatively less fatigue,” Kumpf says. “When it comes to fat loss, it's a good way to burn a fairly high amount of calories in a short amount of time.”

Uses your entire body to increase workout efficiency

Often, this includes compound exercises that work multiple muscle groups at the same time. And, most importantly, you’ll be doing a lot of work in a short amount of time, with specifically programmed short periods of rest. The exact duration of the movement and the rest can be different depending on the workout you are doing. But common work-to-rest ratios are 1:1, 2:1, and 3:1.

Challenges your body to use specific energy pathways

Because two of the energy pathways (immediate and short-term) lead to excess post-exercise oxygen consumption, or EPOC, and that’s when the body’s oxygen consumption remains elevated after a tough workout. During this time, the metabolism is also elevated and you keep burning calories and fat ³. This is also known as the after-burn period.

You spend less time to get the same results

Exercise is all about the effort. In fact, it’s the effort, rather than the time spent, that gets the results. Instead of spending one hour doing steady-state exercise, metabolic training can be short and focused, with peaks and valleys of work, designed to give you a big bang for your buck. These workouts can range from just 10 minutes to 30 or 35 minutes.

In fact, one study of healthy college-aged women and men, found that both longer endurance cycling sessions and short and intense interval-based cycling sessions resulted in an equal increase in skeletal muscle oxidative capacity⁴. 

If you’re always putting off your workout because you just don’t have time for it, then give metabolic workouts a try!