Lower intensity exercise burns more fat. If ever there has been a statement that is true but is presented in possibly the most misleading way, this is it. Consider this example: If I tell you Im going to give you 90% of my income, youd probably be pretty excited until you find out that I make $1000 per year. Nine hundred dollars is nice, but not what you were expecting from 90%. Now, if I told you I was going to give you 0.1 % of my income, youd probably not get too worked up over that until you find out that I make $10 million. Id be dropping a cool $100K in your lap. The percentages are what is misleading. How does this apply to fat loss? Simple, the common misconception is that lower intensity exercise burns more fat. Your body has two sources of fuel for activity - stored fat and carbs. It is ALWAYS using both. Your body simply adjusts the mixture according to what is needed based on the intensity of effort at any given moment - whether you are working out, cutting the lawn, or helping a friend move heavy furniture. At a lower intensity of activity, your body burns a higher percentage of calories from fat, but it may not burn more fat. If lower intensity workouts really do lead to the most fat loss, then the lowest intensity possible workout should be ideal. Lying on the couch is lowest form of activity (your body is still burning calories) you can do. Clearly, this is ridiculous. At rest, your body burns fat and carbs in approximately the following amounts:
Carbs = 47%
Fats = 53% At a moderately paced run (65% of VO2 Max or 6 miles per hour), the following percentages of calories are from fat:
Men = 20%
Women = 42% Clearly, its better to be at rest if you want to burn more fat? Right? Hold on a minute. At rest, we burn around 70 calories per hour (37 calories from fat). At our sample run of 6 miles per hour, the calorie burn is as follows: Men = 794 calories per hour (794*20% = 158 calories from fat) Women = 680 calories per hour (680*42% = 286 calories from fat) (Estimated for 40 year old, 58, 150 pound female, 175 pound male) The question is this: Do you want to burn a higher percentage of fat or more actual fat calories? It should be clear that you should strive to burn more fat calories as this will reduce the amount of stored body fat you carry. How can you use this in your workouts? The least complicated way is to alternate days of interval training (varying intensity) with days of steady state training (consistent intensity). This will insure that you are spending ample time at the higher intensities while also allowing for some lower intensity training to keep from burning out and to keep your body guessing. (Note: If you do the same calculation with walking for one hour, you will find that the pattern is the same. The calories burned from fat lies between our numbers for lying down and running. I used a ridiculous example of lying on a couch to more clearly illustrate the ridiculousness of thinking that lower intensity exercise burns more fat.) |
