To lose weight, you need a negative energy balance: your body must burn more energy (calories) than it takes in through food. You can achieve this in two ways: by eating less or by exercising more through cardio. Which is best?

COMBINATION

As far as we’re concerned, you don’t have to choose right away. Suppose you want to achieve an energy deficit of 500 calories, you can easily achieve that by eating a little less (250 kcal) and exercising a little more through cardio (250 kcal). A combination, then.

A calorie-restricted diet is generally considered the foundation for an energy deficit. However, cardio is good for your health, and the extra calories you burn mean you don’t need to diet as rigorously. Daytime exercise also promotes better sleep. Some cardio during a cut is therefore definitely recommended.

WITH AN EVEN GREATER ENERGY DEFICIT

The question of which of the two is best only really matters when you need to burn even more calories. This is the case with metabolic adaptation: your body increasingly conserves energy, and you have to burn more and more calories to maintain the energy deficit.

Are you feeling increasingly hungry? Then do more cardio. Are you getting more and more tired (from strength training plus cardio)? Then reduce your calorie intake.

Source: Instagram, rpstrength.

LIMIT OF CARDIO

We believe there’s a limit to the amount of cardio you do. The reasons for this are:

• Cardio is time-consuming. It’s much easier to eat fewer calories than to burn them through exercise;
• Cardio causes more fatigue, while during a cut you already need a lot of energy to maintain your strength training;
• Many strength athletes find cardio boring;
• Cardio itself also makes you hungry;
• Sometimes doing cardio is compensated by less spontaneous movement (NEAT, see this article);
• Cardio becomes less effective over time due to adaptation;
• High amounts of cardio can jeopardize muscle mass preservation. More on that in this article.

CONCLUSION AND ADVICE

How much cardio you do during a cut is a matter of preference. But as far as we’re concerned, a calorie-restricted diet is the foundation, and cardio is a supplement.

Don’t do excessive amounts of cardio and always do cardio after strength training.