Why Aerobic Training Makes You Fat

Arguably the number one reason people exercise is to lower their bodyfat. Unfortunately most get it wrong!  For the average trainee and that’s most of us, bodyfat percentage has a direct correlation with nutritional quality. 

Nutrition aside, the most popular activity to lower bodyfat is aerobic training or cardio as its known in gym land.  Typical “gym cardio activities” include stationary bike, treadmill exercise, cross-trainers and numerous aerobic styled group exercise classes.

Ever taken a really good look at the various physiques in a gym?  Look closely and you’ll see that most people doing cardio are overweight.  Step into the free weights area of most gyms and not surprisingly the physiques are leaner.  Interestingly, some of the most popular group fitness classes on the planet use some type of free weight resistance…funny that!

How can this be, if cardio is the best path to leanness?  Has the light bulb gone off yet? 

Here’s what you get from traditional “gym cardio activities”:

 

Increased respiratory rate                                                          tick                          

Improved (activity specific) aerobic capacity                             tick

Loss of lean muscle                                                                   not happy Jan

Risk of overuse injury                                                                not happy Jan

Lower EPOC (Excess Post-exercise Oxygen Consumption)       not happy Jan

 

By definition, cardio refers to any exercise where the heart and lungs are being asked to perform beyond sedentary work. This could be cycling, running, swimming, tennis, crossfitting, kettlebelling, swinging a sledge hammer, yes ~ weight training, circuits, etc. If you elevate your heart rate and respiration rate, cardiovascular work is occurring.

Aerobic training refers to one particular type of cardiovascular work. Aerobic literally means “with oxygen” and is a state of relatively low exercise intensity, which can be maintained for extended periods. As long as sufficient oxygen is being supplied to the working muscles, the exercise can be continued. All aerobic training is cardiovascular in nature. Not all cardiovascular training is aerobic.

 

Steady state aerobic training is a bad choice for lowering bodyfat and can actually create an environment for fat gain NOT fatloss!

Here’s why:

Yes it burns calories…and?

Yes the muscles are working and their demand for oxygen is elevated…but many activities demand muscular work and increased oxygen use: weight training, sprinting, manual labour, household chores, shopping, gardening, etc. All these activities will expend calories via muscular work. Sorry, no extra points for aerobic training.

 

The fat burning zone does not exist 

The concept of the fat burning zone states that the body burns a greater amount of fat at lower intensity aerobic exercise than it does at higher intensities. This ideal is widely misunderstood.

It's true that the body burns a greater percentage of fat at lower intensities than at higher intensities.  Taking this concept to its illogical conclusion…the body will burn a greater percentage of fat sitting on the couch watching TV…yeah right! The key to this argument is the percentages.

At lower intensities of exercise the body may burn 50% of energy from fat, while at higher intensities it may only use 30% from fat fuel.

However, at higher exercise intensities more TOTAL energy is expended and therefore, more fat fuel will be utilized overall than at lower intensities.

Here’s a real world example: Elite sprinters are leaner (read lower bodyfat) than marathon runners.  This is due to the sprinters’ greater muscle mass and consider sprinters cover  much less total mileage in their training and NEVER perform aerobically! Go figure!  

 

Aerobic training maintains and can increase fatness

Here’s the kicker and it sounds like training heresy, but close examination of the aerobic conundrum illustrates the point. This is why traditional aerobic training in general is highly undesirable and a waste of time, unless of course you enjoy it.

The only tissue in the body that burns fat is muscle. Aerobic training demands work from the muscles, but at a cost of losing NOT maintaining muscle. 

Aerobic training makes muscles more efficient at using fat fuel.  Efficiency means utilizing less not more! 

As a car becomes more efficient, it uses less not more fuel!  From a fat burning perspective do you want the engine of 1.3L hatch or fuel guzzling supercharged turbo engine!

Light Bulb Moment…if muscle is the only tissue that burns fat and aerobic training reduces muscle mass, essentially aerobic training creates a smaller [read less muscular] & most likely fatter machine. This is a highly ineffective template for fatloss. Call me crazy, but I bet dollars for doughnuts most people would prefer to be strong and lean, NOT smaller, weaker and with potentially the same or higher bodyfat percentage.

The body literally adapts to activities imposed upon it and counter intuitively will respond in an opposing manner endeavoring to maintain equilibrium. Here are some familiar scenarios:

Don't drink enough water and the body tries to retain water. [Fluid retention].

Don’t consume enough carbohydrate and the body tries to store it. [Marathoners carbo loading]. 

Weight training actually breaks muscle down. [Recovery builds it up]. 

And here’s the real kicker; burn a heap of calories and expend a ton of energy with aerobic training and the body adapts to this exercise by:-

Slowing metabolism, which promotes storage not usage of energy, IE fat and carbs.  Essentially storing more fuel (fat & sugar) in a body with less muscle and therefore a lower metabolism; creating a smaller fatter machine AKA a skinny fat person. Ouch!

Does weight training build muscle? No it doesn't. What actually occurs is a breakdown of muscle tissue and the body adapts during recovery by building muscle.

Stated again, if you burn a ton of calories doing aerobic training, that same body adapts to aerobic exercise by slowing your metabolism and allowing your body to store more energy...yes, that's right fat and sugur is the body's energy currency. Bravo!

 

Aerobic Training Does Not Raise Your Metabolism

Metabolism is largely a function of how much muscle you carry, recall EPOC. Remember aerobic training reduces muscle, effectively minimizing resting metabolic rate. Aerobic gurus will argue that performing aerobic activity burns calories…true, but what about the other 23 hours…having less metabolically active tissue because of reduced muscle mass; means no elevation in resting metabolic rate.  Not happy Jan!

The biggest problem with aerobic training is that you get better at it. That’s right you become more efficient!  Recollect…do you want to be a 1.3L fuel efficient buzz box or a supercharged (fat) fuel guzzling machine.

In weight training, as you get better, you add more bar weight, potentially progress is never-ending. Have you ever heard a sports coach ridicule an athlete for being to strong! Or doctors criticize a patient for having strong bones and a robust posture!

For example aerobically the work output required to run 5K’s will become less as you get fitter. So for continued improvement you either run further (do more work for the same amount of calories) or you run faster. Going further kind of defeats the purpose, but that’s another article. Remember, as you get fitter less work is required and therefore less FAT is utilized.

Where’s the joy in running 40 minutes to burn the calories you once utilized in 30 minutes? Going faster involves the same problem. Eventually, the new speed becomes too easy and you have to raise intensity to achieve the same benefits.

With anaerobic energy systems ~ IE weight training ~ there is always progression

Unless you’re an elite endurance athlete ~ and even they train anaerobically and lift weights ~ aerobically there is an end point. Your training will reach an intensity whereby the aerobic zone ends and the anaerobic system begins.

At some point your training will require increased workloads and you’ll train at higher intensities.  This means anaerobic metabolism becomes  the dominant training system.  Now you’re not aerobic!

The argument being that if at some point you have to stop performing aerobic training to gain the desired benefits, why not perform anaerobic work in the first place?  Call me synical, but that's a no brainer. What type of anaerobic training gives you most bang for your buck…you guessed it ~ any number of weight training protocols. 

See you under the bar.