Myth: It is necessary to perform cardio on a regular basis to lose fat.
Truth: Cardio is not necessary for fat loss, and contributes relatively little to a fat loss program compared to high intensity strength training.
To lose fat it is necessary to create a calorie deficit – you must consume fewer calories than you expend so the body obtains the difference from your fat stores. While overall activity level has an effect on daily calorie expenditure, additional “cardio” (steady state or interval training) burns relatively few calories even if performed for an hour or more at moderate intensity daily. A greater calorie deficit can be achieved by simply restricting calorie intake, with little time investment other than the few minutes required for planning and recording meals.
The most important benefit of exercise to a fat loss program is not the calories expended during workouts, but the maintenance of muscle tissue while fat is lost. This requires strength training. There is a direct relationship between lean body mass, particularly muscle mass, and metabolic rate – more muscle equals a higher metabolic rate. If calorie intake is reduced significantly without regular, consistent strength training, muscle tends to be lost along with fat resulting in a reduced metabolic rate. Cardio does nothing to prevent muscle loss and may even accelerate it.
While cardio may make a small contribution to a fat loss program, it is highly overrated, and of minimal importance compared to calorie restriction. Contrary to the wishful thinking of the crowds that flock to the treadmills, stairmasters and elliptical machines on Monday night after a weekend of overeating and excessive alcohol consumption, no amount of cardio will make up for poor eating habits. In fact, if calorie intake is not being measured and recorded, cardio will probably make almost no difference at all because it will increase appetite.
The most effective approach for the majority of people is a combination of high intensity strength training and reduced calorie intake. The reduced calorie intake creates the deficit necessary to force the body to use its fat stores for energy, while the high intensity strength training prevents loss of muscle mass.
I currently have one personal training client who lost over seventy pounds of fat in nine months, and another who lost one hundred and ten pounds of fat in a little over a year. Both perform high intensity strength training and keep close track of their calorie intake, but do no cardio. Numerous clients of mine have achieved similar results over the past fifteen years with the same approach. I once reduced my bodyfat to the low single digits for a bodybuilding competition with no cardio, proving one can become as lean as possible with high intensity strength training and strict diet alone.