Fat Burning Zone

With each of my blogs, I will try to sum up my main article at the beginning of each blog since most of my blogs might involve “jibberish” to most.   Note: My next blog will go over some basic terminology of fitness

To sum it up: Fat Burning involves a LONGER duration, at a LOW intensity while REDUCING and/or MAINTAINING your total dietary consumption.  “Fat Burning Zone” = aerobic activity that does not produce significant amounts of lactic acid.   Read below and learn about fat oxidation, and understand that a calorie is NOT just a calorie.  

How can you optimize Fat loss with aerobic exercise?  

Theory A: Perform aerobic exercise at a lower intensity to augment fat-oxidation and fat loss.   Intensity varies from each individual but should be between 55-70% of the Individual’s Maximum Heart Rate (MHR).   Use the Karvonen Formula, from my previous blog post, for a more detailed number designed for you!

Theory B: Exercise burns calories and the more calories you burn the more fat you lose.   It won’t matter if you run 20, 30, or 40 minutes. You can use the Absolute (total calories burned) approach vs.  the Relative (proportional-fat calories burned) approach.  

Examples:

1)    For those car fans:    A Mustang GT vs. a Honda S2000

The Mustang GT has -4.6 litre engine and 300 horsepower.

The Honda S2000 has 2.2 litre engine and 237 horsepower.

Yes, technically, the Mustang GT may be “more powerful,” but the Honda S2000 gets more PER litre (107 hp/L vs. 375hp/L).   The mustang needs large superchargers to accomplish what a Honda does with valve timing.  

2)    In terms of a sprinter vs. a ballet dancer:  The sprinter may have speed, and reach the finish line quickly, but the dancer has the grace, stamina and longevity.   You can dance for hours but only sprint for seconds.   Bring back memories of the Tortoise and the Hare?

Science has proven that when an individual exercises closer to 100% of aerobic capacity, the body’s immediate calories are derived from carbohydrates, not fat.   When the individual recovers, the body will slowly return to a mixed source (Fat, Carbohydrate, and Protein) of energy.  The assertions with Theory B are made without accounting for Respiratory Exchange Ratio (RER).   Basically, Carbon dioxide used over oxygen used.   This is the ratio of biochemical reflection of what substrate (fat, carb, protein) is being oxidized (METABOLIZED OR BURNED) during exercise or rest.   The foundation of the “Fat Burning Zone” lies in the individual’s metabolic rates that dictate the source of energy (fat, carb, protein).   Fat Burning involves a LONGER duration, at a LOW intensity while REDUCING and/or MAINTAINING your total dietary consumption.  

Higher intensity involves more soreness and fatigue.   I like to be around 65% of my MHR.   That is when my body burns fat the best.   What about your body?   Test it and find out!   Give yourself 3 weeks with each intensity.   Mark your results.   Start with the low intensity (50-65%), then for the next 3 weeks shoot for a medium intensity (65-75%), and for the last three weeks go for the higher intensity (75-85%).   That right there is a 9-week program with an aerobic exercise, 2-3x a week, for a duration of 20 minutes minimum.   Be sure to maintain a well-balanced diet throughout the process.

Fat Oxidation

            When the exercise intensity increases, the relative proportions of fat oxidation decreases while that of carbohydrate increases.   Is the individual’s interest: Absolute: How much fat is oxidized? or Relative: The percentage of energy from fat during exercise?

In a relative sense, the lower the exercise intensity, the greater the reliance on fat as a substrate for energy.  In an absolute sense, during more intense exercises, Total Caloric Expenditure is much higher.   For the most part, the body can interconvert one macronutrient (and there are 7) to another with the exception of fat-carbohydrate conversion, hence the “fat-buring zone” debate.   “A calorie is a calorie regardless of the source” is a typical answer.  

BUT…

A calorie is NOT just a calorie       

            If a calorie is just a calorie, then three diets at the same calorie level, the first composed of 100% protein, the second 100% carbohydrates and the third 100% fats, would all have the same effect on body composition. A diet of 100% tuna fish (lean protein) will not have the same effect as a diet of 100% potato chips (fat and carbohydrate). Nothing should be 100% of one thing too!  You need balance. J   Calorie balance is the most important issue in fat loss but there's more to it than that. Other variables include the thermic effect of food, the effect of each food on hormones and blood sugar levels and the macronutrient ratios of each meal, etc.  But a Nutritionist can lay you down with all that hefty information.

            A misconception about fat loss is the scientific approach that "a calorie is just a calorie" and the only thing that matters is calories in vs.  calories out.   If fat loss were that simple, then you could eat anything you wanted and you would still lose fat as long as your calories were below maintenance. For example, you could eat nothing but chocolate candy bars and drinks nothing but soda and if you were 100 calories under maintenance, you'd lose weight.    I hope your common sense told you this isn't true.

There are two ways to stop or slow the fat burning system.

1)    Consumption of high carbohydrates (note: Simple Carbs tend to move insulin production and move fat storage. So BALANCE!).

2)    Production of Lactic Acid.   Produced during high intense anaerobic exercises.   Lactic Acid interferes with the fat mobilizing hormones and the fat burning enzymes of the body.  

“Fat Burning Zone” = aerobic activity that does not produce significant amounts of lactic acid.   As the individual becomes more physically fit, Lactate Threshold (appearance of Lactic Acid in the blood) will increase.   Lactate Threshold allows more fat to be burned over a wide variety of exercise intensities.  

So, engage in all forms!   Utilize a well-balanced regime incorporating all aspects of cardiovascular exercises.   Optimal Health and Homeostasis!   Get the miles covered, not just the time.  

The journey continues….   Let’s learn the language of fitness a little bit!