Which Cardiovascular Intensity is Best for Fat Loss

I am launching a series on fat loss myths and  truths, this month we will look at cardiovascular training intensity and how it pertains to effective fat loss.  I think that everyone will agree that cardiovascular training is a crucial element in the battle of the bulge.  However, just as much confusion lies in what intensity and how long the intensity should be continued when performing your cardio workouts.  So, this brings us to the question at hand – which intensity is best for fat loss?  Low intensity long duration, high intensity short duration or an interval type of training.

First off, let’s look at the three aforementioned variations in intensity and durations.

  • For      years the standard edict was low intensity long duration.  The reasoning behind this is that at      60-70% of your maximum heart rate (calculated by subtracting your age from 220), you burn a larger percentage of fat calories to perform the activity.  This sounds good; a large % of calories used come from fat, do your cardio for 45 – 60  minutes and in no time you are ready for the beach.  Right?       Not so fast my friend.  You      do consume by far the largest % of calories used for the activity from fat      stores, but the larger percentage is of actually a relatively small      number.  Would you like to have 80%      of one hundred dollars, or 10% of a million dollars?  So with this logic, we can’t just look      at the higher percentage as a final measuring stick.


  • The      second intensity level and duration is high intensity shorter      duration.  We are talking about a      heart rate that equates to 80-90% of maximum heart rate for an activity      that lasts approximately 25-30 minutes.       This moves quickly from the aerobic (with oxygen) status to an      anaerobic (without oxygen present) classification.  I know what you are thinking; “If you      aint got no oxygen, you can’t burn no fat, capice” (all you Tony Sopranos      wannabes).  Well to an extent you      are right.  You will not use a      considerable amount of fat (triglycerides) for the production of energy      when you are in an anaerobic state.       However, you will still      manufacture some of your energy      from fat without oxygen present (remember, all three energy systems are      constantly working, albeit in different ratios and proportions.  Based upon the intensity and duration of      the activity.)  So in this scenario      we still manufacture some energy from fat, however it is a smaller %.  Get this; it is a smaller % of an      overall larger number.  Would you      like to have 80% of one hundred dollars, or 10% of a million dollars?  Count me in for the 10% of a cool mill,      and you?  Sounds like we solved the      case, not so fast my friend, we aren’t done yet.


  • What      if in this third scenario we took the best of both the intensities already      mentioned and morphed them into one.       A period of time of high intensity, followed by a recovery period of      a low intensity.  This sounds like      it could be it.  You get an overall      larger number of calories than low intensity long duration, and you get      the benefit of using a large degree of calories from the body’s fat stores      (triglycerides) during the low intensity portions.  An added benefit of this type of      interval training is that your body will use more overall calories      throughout the day, as it takes time to downshift from the back and forth      of intensities and you burn more calories even after the activity      concludes.  This has to be the      answer, right?


I may have forgotten to mention one crucial element in all of this.  Your body adapts very quickly to cardiovascular activity.  The reason is this; your body is constantly searching for a point of homeostasis (or evenness).  To be more to the point, your body is perfectly happy with the fat stores you have saddled it with.  Even though personally I don’t believe in it, our bodies function under the premise of evolution.  It doesn’t know that there is a burger joint, pizza joint or CheeseSteak joint on every street corner, it still thinks that we have to hunt, fish and gather for our food.  So it is constantly looking to keep any fat stores for an impending famine.  The second part of this is that since the body adapts very quickly to cardio, it becomes more efficient at performing the activity.  After time and again of being exposed to your 45 minute run at 10:00 / mile, the readout on the treadmill that states 400 calories used for your run (which is never 100% accurate anyway), is nowhere near 400 calories.  Your body has adapted by becoming more efficient at performing that activity at that intensity for that time.  So the 400 calories used on the readout is now really like 300 calories. As I am sure you would agree, not a very desirable effect for fat loss.


The answer lies in variety.  In order to keep your body in a constant fat burning state, vary your intensities between the three described in this article.  Do some of your cardio at a low intensity for a long duration (45 -60 mins),  perform some at a very high intensity for a short duration (25-30 mins) and finally do intervals, varying higher intensity with a recovery period of lower intensity for approximately 30 mins.  Changing between the three intensities each time you perform your cardiovascular workouts will keep your body from becoming a stagnant and less effective fat burner and you will be shredded in no time.


  1. Do You Have a Slow Metabolism? Find Out Now! | Fit for Faith Ministries - October 25, 2013

    […] second way is to decrease body fat stores by performing cardiovascular activity and vary your intensity and duration of the continuous rhythmic movement. By varying your intensity […]

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