Is it better to do cardio before or after workout?


Cardio first is like mining for gold with a shovel. To go through a single layer, 32 scoops must be removed. It will take some time, but you will eventually see gold.

Photo by: Mercey Livingston

Cardio is criticized by so-called “serious lifters,” although it is done exclusively by 60% of those who enter the gym after 5 p.m. But who is accurate, and what is the best formula for progress?

Is there a magic weight-training-to-cardio ratio that should be followed? Should cardio be foregone in favor of a higher dose of strength training? Is it true that doing cardio before a workout ruins your gains?

If your aim in training is to lose weight and look better shirtless, then your goal on a molecular level is to burn up all of your muscle glycogen in order to start burning fat as fuel.

Here’s how it works.

ATP (adenosine triphosphate) is the fuel that your muscles require to contract, but each muscle contains a limited amount, and once it’s gone, your body must generate more.

In your body, there are three major energy systems at work. I will just discuss two of them here.

Anaerobic system (lactic acid system):

What it does: It dissolves glycogen through a complex chemical mechanism that produces lactic acid as a byproduct, which is responsible for the intense burn you experience after trekking up a long hill or performing a long set of biceps curls.

Used for: High-intensity, short-duration exercises such as sprinting and weight training.

Anaerobic System Conversion: 1 molecule glycogen = 3 ATP.

Photo by: Amacsports

Aerobic System (oxygen system)

What it does: It uses an even more sophisticated chemical reaction to convert glycogen into ATP with the help of oxygen (remember the KREB cycle from 10th grade?). This is why you breathe more heavily during cardio than weight exercise since your body needs more and more oxygen to keep you going.

Used for: Long-duration, moderate-intensity exercises such as running or rowing. Because this system kicks in after 8-10 minutes, jogging seems significantly easier after the first mile.

In this cycle, each molecule of glycogen can be broken down into 32 molecules of ATP, which is ideal for long-term exercise.

Aerobic System Conversion: 1 molecule glycogen = 32 ATP.

Photo by: Amacsports

This is a far more efficient conversion that can give more long-term energy than the anaerobic system.

Depending on the activity, it can take up to an hour to burn up all of the glycogen stored in your cells and liver, at which point the body is forced to start using fat for fuel. Which is the goal for the majority of us who are attempting to lose winter weight and fit into last year’s swimsuit.

This hour marker stated above is also heavily reliant on nutrition, which is why a low-carb diet, especially when combined with exercise, can work incredibly well for fat loss. The more carbohydrates consumed before to an exercise, the more glycogen remains in your system to be burned off before fat can be used as fuel.

Cardio before a workout. Energy system trained: Aerobic.

Cardio after the workout. Energy System trained: Anaerobic.

Pros and Cons

Cardio First

Cardio before a workout is beneficial since it allows you to burn more calories over the course of the workout by raising your heart rate at the start. This raises your body’s internal temperature and increases the metabolic demands imposed on it.

This guarantees that your heart rate remains raised during the workout, increasing overall calories burned.

The drawback is that you will be more exhausted after performing cardio and will not have as much energy to commit to resistance training, which is better for long-term physique improvements.

Cardio Last

Because the aerobic system is far more efficient at producing ATP, doing weight training first helps you to get to the fat-burning part of the workout much faster than if you did cardio first.

Concentrating the majority of your energy on improving your strength and physique in the weight room will lead to better outcomes. After all of the glycogen has been drained, cardio will result in a substantially larger proportion of fat being burned.

The disadvantage of this method is that it might be tough to work hard at weight training and then immediately push yourself through a cardio workout.

Imagine burning fat as if you were mining for gold. Before you can get to the gold, you must first work your way through layers of dirt and rock (muscle glycogen).

So, which is better?

Cardio first is like mining for gold with a shovel. To go through a single layer, 32 scoops must be removed. It will take some time, but you will finally see gold.

Doing resistance training first is like reaching the same dig site with a backhoe. Because of your diesel-powered machinery, you only need three scoops to go through one layer.

So, if you’re short on time or simply want to go back to your family, pets, or World of Warcraft character, start with the weights and save the cardio for last.

To gain the most benefit, aim for a 45-minute workout followed by 20-30 minutes of aerobic intervals three times per week.