Cardio Can Make You Fat

October 22, 2015 | John Paul Catanzaro

Cardio Can Make You Fat

Q: I’m still very much confused regarding cardio intensity. One book says keep it low intensity (no more than 60% of maximum heart rate) and go for distance. Another book says to use high intensity (80% or more) and go for as long and hard as you can. The goal is to burn fat. Each book has great arguments for their approach. Which one is accurate?

A: The high-intensity approach is far more effective for burning fat in the long run. Without getting into a lengthy discussion on this topic, here’s how things work in a nutshell.

At a lower intensity, your body prefers fat for fuel. Yes, this is true, but after a while of doing this type of activity, your body adapts by actually laying down fat to become more efficient at the given task and this usually occurs in the lower body.

Although a higher relative amount of fat is burned during low-intensity cardio, a greater absolute amount is burned with high-intensity cardio and in less time.

Furthermore, the excess post-exercise oxygen consumption (referred to as the “afterburn” effect) is greater for a longer duration following higher intensity work. In other words, your metabolism is much higher for a longer period of time post-workout with high-intensity cardio.

It’s also important to know that higher lactic acid levels are produced with high-intensity cardio. There’s a direct correlation with lactic acid and growth hormone, a potent fat-burner. Therefore, the more lactic acid you produce, the more growth hormone you release, and ultimately the more fat you burn!

Bottom Line: If the goal is to burn fat, do high-intensity cardio in the form of interval training and you’ll get great results. See page 126 of The Elite Trainer to learn how to incorporate interval training in a body composition regimen.