The Fallacy of Cardio for Fat Loss

By Mark Clevenger
December 31st 2016

I started writing this piece the other day by tactfully addressing the fat loss ignorance that permeates our culture. After 3 pages of teasing out all the misused and misunderstood information I still hadn’t started addressing the real science, the facts, about fat loss and exercise. So I decided to scrap it and write a blunt post backed by science. After all, the best argument you can make for bad or misused information, are facts.

Fact #1: Your diet dictates fat gain and fat loss1. Fat loss is simply a matter of calories out (exercise) > calories in (food). Your body must be a state of caloric deficit to lose fat1.  No if’s, and’s, or but’s about it. If you eat more than you use, you will not lose weight. You can believe whatever you want about your buddy who used the pop tart diet, or took a magic pill through some Ponzi scheme, but this is a proven fact.

Fact #2: Resistance training is better than aerobic training at burning fat2. This is because resistance training for fat loss is shown to reduce fat and preserve fat free mass (muscle) during times of caloric deficit2. Aerobic training (cardio) on the other hand shows a reduction in both fat and fat free mass2. Reduced lean mass is contrary to your fat loss goals. Don’t believe me? See Fact #3.

Fact #3: Muscle burns energy substrates (fat, carbohydrate, and protein) for fuel to perform work3.  With this fact known we can logically conclude that someone with 100lbs of fat free mass uses twice as much energy as someone with 50lbs of fat free mass doing the same amount of work. So having a little extra muscle only helps you get the desired effect of fat loss quicker. Muscle is our friend in the fight against fat loss.

I can hear the women reading this now in my head as I write, ‘but I don’t want to get bulky.’

Fact #4: If you’re lifting weights while on a caloric deficit diet you won’t put on mass. The body doesn’t have the substrate quantities necessary (because of the deficit) to build new muscle and make you ‘bulky.’

What should you take from all this? First and foremost, your diet dictates fat gain or fat loss1. Second, resistance training is better than standalone ‘cardio’ for fat loss because it preserves muscle while burning fat2. This resistance training will not make you bulky when dieting, regardless of your gender. Muscle is our friend because it burns substrates, like fat, for fuel. The more muscle we have, the greater potential to burn these substrates. So please, please, please, get off the cardio train at the next available stop and get on the resistance training bus with a one way ticket to less body fat. Or just keep running all the time and complaining to your friends about how you look skinny-fat instead of just skinny.

References:

  1. Hall K.D. What is the required energy deficit per unit weight loss. Int J Obes (Lond). 2008; 32(3): 573-576.
  2. Geliebter A. Maher M.M. Gerace L. Gutin B. Heymsfield S.B. Hashim S.A. Effects of strength or aerobic training on body composition, resting metabolic rate, and peak oxygen consumption in obese dieting subjects. Am J Clin Nut. 1997; 66(3): 557-563.
  3. Gaitanos G.C. Williams C. Boobis L.H. Brooks S. Human muscle metabolism during intermittent maximal exercise. J App Phys. 1993; 75(2): 712-719.