Myth series: #1 “I should just do cardio if i want to burn fat”


Perhaps the oldest fitness myth going around. Let’s dive into this one.

In short, yes; if you want to purely burn fat while you exercise, doing ‘cardiovascular exercise’ (which people commonly associate with things like running, walking on the treadmill, the elliptical, stairmaster at the gym etc.) is what you would want to do. Just prepare to spend a LONG time on the machines, as it takes a long time to burn any significant amount of calories, when compared to a higher intensity workout.

This will be explored further in another chapter in this series (See “The Fat Burning Zone”), but in short, if you are working at between 50 – 65% of your relative heart rate max during exercise; you will be utilising energy from fat cells are your primary fuel source.

As most people you see at the gym trot along on the machines at around this heart rate range; this is where the notion that you have to do ‘cardio’ in order to ‘burn fat’ has come from.

Now, most of the time, when people state they want to ‘burn fat’, what they really mean is “I’m overweight/unhappy with how I look/want to change my body”, which we can reframe as them wanting what’s called a body composition change.

They want to decrease their body fat, and increase their muscle mass.

To appear leaner, more ‘toned’.

Now we have something to work with.

A body composition change is far more straightforward (in theory, in practise it is a bit more tricky).

Simply doing ‘cardio’ is just not going to cut it.

Some form of resistance training needs to be included in order to build muscle; you cannot build any sort of substantial muscle from just the cardio machines at the gym

You’re going to want to include some high intensity, metabolic conditioning in there as well, as this is a far more time efficient, and also effective, means to achieving a reduction in body fat, while simultaneously contributing to increasing your muscle mass.

Think sleds, battle ropes, ball slams etc.

Have you ever noticed how people with a larger amount of muscle mass typically (not in every case, just generally speaking) don’t have a lot of body fat on them?

This is because they are a) burning a substantial amount of calories during their resistance training workouts and b) muscle takes more energy to sustain itself than fat; so an individual with an increased muscle mass will be burning more calories at rest than someone with less muscle.

SUMMARY: If you want to burn predominantly fat, over a very, very lengthy period of time, do ‘cardio’. If you want to reduce body fat AND increase muscle mass (which is what almost everybody wants) in a time efficient way, lift weights and do some form of HIIT as well.