Intensity levels/zones carbs vs. fat burning

tunicaf
tunicaf Posts: 12 Member
in Fitness and Exercise
Met with a new trainer who instructed that I should keep my cardio workouts@ low level intensity zone so that a greater proportion of the calories I burn will come from fat not carbs. This seems a little counter-intuitive to me. I like to push my cardio sessions harder than that (above hr of 140).
Does fat vs. carb matter? Isn't burning more calories than you take in the basic principle of weightloss?

Replies

  • MeanderingMammal
    MeanderingMammal Posts: 7,866 Member
    tunicaf wrote: »
    Met with a new trainer who instructed that I should keep my cardio workouts@ low level intensity zone so that a greater proportion of the calories I burn will come from fat not carbs.

    Hope you didn't pay for that advice :)
  • tunicaf
    tunicaf Posts: 12 Member
    I didn't, it was included in my new membership. Thanks for advise.
  • tess5036
    tess5036 Posts: 942 Member
    Quite simply, the faster your heart rate during exercise, the more calories you are likely to be burning.

    Look at no. 4 on this, it explains it quite well

    https://www.webmd.com/fitness-exercise/features/the-truth-about-heart-rate-and-exercise
  • _mr_b
    _mr_b Posts: 302 Member
    Personally I don’t think that point 4 answers the question at all - it says more vigorous exercise burns more calories which is true. It doesn’t however answer the question which revolves around how the body sources those calories.

    It’s called the fat burning zone for a reason. Personally I’ve found exercising at that low an HR to be a bit dull, lots of people do it though and have trained their body to go after fat rather than glucose.
    Me, I’d rather use up my body’s sugars having fun and then let the calorific deficit do the rest.
  • Tacklewasher
    Tacklewasher Posts: 7,122 Member
    tunicaf wrote: »
    Met with a new trainer who instructed that I should keep my cardio workouts@ low level intensity zone so that a greater proportion of the calories I burn will come from fat not carbs. This seems a little counter-intuitive to me. I like to push my cardio sessions harder than that (above hr of 140).
    Does fat vs. carb matter? Isn't burning more calories than you take in the basic principle of weightloss?

    Fat vs carbs doesn't matter for weight loss. It can matter for performance on longer runs, but we are talking past the 1/2 marathon stage (from what I understand).

    If you want to burn more calories, go at a pace you can keep up for longer. If you have a short time frame, then go harder. And mix it up to prevent boredom.
  • jjpptt2
    jjpptt2 Posts: 5,650 Member
    tunicaf wrote: »
    Met with a new trainer who instructed that I should keep my cardio workouts@ low level intensity zone so that a greater proportion of the calories I burn will come from fat not carbs. This seems a little counter-intuitive to me. I like to push my cardio sessions harder than that (above hr of 140).
    Does fat vs. carb matter? Isn't burning more calories than you take in the basic principle of weightloss?

    As long as there aren't endurance cardio goals at play, then yes - you are correct. And while he isn't wrong, he probably isn't helping you as much as he thinks he is.
  • JMcGee2018
    JMcGee2018 Posts: 275 Member
    _mr_b wrote: »
    Personally I don’t think that point 4 answers the question at all - it says more vigorous exercise burns more calories which is true. It doesn’t however answer the question which revolves around how the body sources those calories.

    It’s called the fat burning zone for a reason. Personally I’ve found exercising at that low an HR to be a bit dull, lots of people do it though and have trained their body to go after fat rather than glucose.
    Me, I’d rather use up my body’s sugars having fun and then let the calorific deficit do the rest.

    Exercising in the "fat burning zone" burns a higher % of calories from fat rather than carbs, but higher intensity cardio ends up burning more overall calories, and that difference in higher calories burnt means that you will almost always burn a higher sum of fat calories by working out at a higher intensity, even if the ratio of fat to carbs is flipped so that more carbs are being burned than fat. The whole idea of the fat burning zone is very misleading, because as someone said above, you burn the highest % of fat from activities like sleeping and sitting on the couch, but no one would advise that for weight/fat loss.
  • jjpptt2
    jjpptt2 Posts: 5,650 Member
    edited March 2018
    _mr_b wrote: »
    Personally I don’t think that point 4 answers the question at all - it says more vigorous exercise burns more calories which is true. It doesn’t however answer the question which revolves around how the body sources those calories.

    It’s called the fat burning zone for a reason. Personally I’ve found exercising at that low an HR to be a bit dull, lots of people do it though and have trained their body to go after fat rather than glucose.
    Me, I’d rather use up my body’s sugars having fun and then let the calorific deficit do the rest.

    Except that the fat burned while in the fat burning zone is intramuscular fat, not general body fat deposits (i.e. the stuff you grab when you say "I HATE THESE LOVE HANDLES!"). So even if your goals are body comp related, the fat burning zone does nothing to directly target/address that goal.

    Let's also not forget that you're only burning body fat when blood glucose isn't available as and adequate fuel source. So if you're working out fed, even in a fat burning zone, you probably aren't burning fat as you primary fuel source.

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