Aerobic & Anaerobic Fat Burns?

kenuk1
kenuk1 Posts: 64 Member
in Fitness and Exercise
Hi all,

I can comfortably run 10k at the moment and today I decided to do the 7km from home to work, I use a Wahoo Blue HRM paired with Runtastic and have been syncing for the last 2 months with MFP, I'm no fitness guru and have some confusion of the different Heart Rate Zones and what is seemingly happening to my weight loss/fat burn during my run.

Today's run was mostly on road with a slow run for approx 1 mile in overgrown woodland (3km section)break down is as follows:


7.00 km 6:11 min/km 9.69 km/h 42:55

1.00 km 5:22 min/km 11.17 km/h 5:23
2.00 km 5:24 min/km 11.11 km/h 10:50
3.00 km 7:54 min/km 7.59 km/h 18:53
4.00 km 5:58 min/km 10.03 km/h 24:43
5.00 km 6:27 min/km 9.30 km/h 31:20
6.00 km 5:32 min/km 10.83 km/h 36:47

I was fairly happy with this then I looked at my zones and the percentage of time my heart rate was in each;

Red Line 169-180 1.36%
Anaerobic 159-169 46.31%
Aerobic 148-159 38.23%
Fat Burning 138-148 6.75%
Easy 127-138 0.46%
Not in any zone 1.36% (Maybe I died a little on one of the hills here:) felt like it.)

My target is to lose weight and burn fat, but my question is, whats happening to my body during this run, ideally, do I stay in a heart rate of 138 - 148 to burn fat, and if I go over that (this is stupid maybe) am I still burning fat whilst in Aerobic and Anaerobic??

Really appreciate any help on this, even if someone say's simply, you burn fat in all those zones...but if anyone else can tell me the optimum heart rate, or does this depend on the person that would be useful aswell.

Thanks muchly!

Replies

  • InFitRealm
    InFitRealm Posts: 36 Member
    Hi there,

    for a very long a statement to work out on 60-65% to burn fat was glorified. And it's true that during a work out your body takes energy mainly from fat with this rate. The higher one (so called fitness zone) aggregates energy from carbs etc.
    BUT
    for some time now the state "exercise with fat burning zone" is no longer a rule of thumb. Please have a look at so called "after burn" effect after working out with "fitness zone". Basically it was proven that in fitness zone you indeed use the carbs, but after the work out, the body is still stimulated and burns more fat. So all in all the results may be similiar or theoritcally even better, as during work out you burn carbs (that if excessive will turn into fat afterwards) and later on you burn fat (after burn effect).
    Of course the rate of fat burnt in fat zone and fitness zone/after burn depends on the type of your exercise, your body composition, diet etc. So no golden rule applies. Both should give some desired effect espiecially when we consider running, not weight lifting.
  • kenuk1
    kenuk1 Posts: 64 Member
    So based on what you're saying, whilst in the Aerobic and Anaerobic, I'm burning carbohydrates, as opposed to body fat? Then, once if finished the run, I am burning fat? I'm still confused as you will probably tell by this response lol.
  • stubnitz
    stubnitz Posts: 2 Member
    Are you sure that your heart rates are configured correctly? You've spent nearly half of the run in zone 4, which seems awfully high to me, particularly considering the pace that you were running at.

    Check the settings on your device, you may need to change your stats.

    To answer your question, when you go anaerobic your muscles start using stored glucose for energy.
  • InFitRealm
    InFitRealm Posts: 36 Member
    It's not an all or nothing deal. In fat zone you also use carbs and in fitness zone you also lose fat. But the proportions of what is used changes. The fat zone mainly uses fat, the fitness zone mainly uses carbs, but on the other hand after work out your organism is still on-going and burns more fat than it would without exercising.

    Another thing is that usually in fitness zone you burn more kcal. so this percentage of what is burnt is also counted from a higher base.

    So if you want to lose and you're running you're on a good way.

    Most of the runners (long distance ones and not only olympics) work on fitness zone and all of them are very slim, aren't they :D? Just go to see some marathon run.

    If you eat at deficit and work out you should achieve your goal.
  • kenuk1
    kenuk1 Posts: 64 Member
    According to runnersworld.com, my heart rate should be 182.8max - those zones are set by Runtastic based on my age/weight etc?
    I'm not exactly skinny at 92.5KG, almost 40 years old, if you can enlighten me on what my zones should be changed to I'll try and do it, as I say, I rely on my HRM and Runtastic to do the calcs...
  • kenuk1
    kenuk1 Posts: 64 Member
    It's not an all or nothing deal. In fat zone you also use carbs and in fitness zone you also lose fat. But the proportions of what is used changes. The fat zone mainly uses fat, the fitness zone mainly uses carbs, but on the other hand after work out your organism is still on-going and burns more fat than it would without exercising.

    Another thing is that usually in fitness zone you burn more kcal. so this percentage of what is burnt is also counted from a higher base.

    So if you want to lose and you're running you're on a good way.

    Most of the runners (long distance ones and not only olympics) work on fitness zone and all of them are very slim, aren't they :D? Just go to see some marathon run.

    If you eat at deficit and work out you should achieve your goal.

    Thanks, thats kinda making sense, I am on a cal deficit, 1500 a day and with exercise often see's me with 400 - 500 cals left over.

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