Questioning Heart Rate Zones (Fat Burn vs An/Aerobic)

paulbsr

I have been doing quite well. Started at 300lb in Feb and now on 245lb. Target 200lb.
I religiously use MFP. After 2 months I decided to escalate to a HRMonitor + iCardio/DigiFit.

The HRM then uncovered that my Cardio exercise is relatively intense - I exercise 2.5 hours a day for 5 days a week. On average, my HR does not go below 140bpm for 120 mins out of that 150 mins. This is achieved with a combination of Squash, ArcTrainer, Stairmaster, HIIT, Swimming and Resistance each days (it's during the resistance that my HR dips below 140bpm)

What confuses me is that the iCardio app shows the Fat Burn zone down there is the <120bpm. I think I get it that it's that way because at low BPM your Heart/Lungs/Blood can get oxygen to the required muscle-groups ("aerobic") where as at higher BPM energy is delivered to the muscles differently ("anaerobic").

So if i wanna loose tons of weight I have to opt for a low-intensity long-duration borefest?

sijomial

It's not so much aerobic v. anaerobic as the proportion of glycogen to fat used as fuel changes with intensity. Don't focus on the fuel used during exercise as it's just about irrelevant.

The reduction in body fat over time comes from your calorie deficit.

HR zones have relevance for training towards fitness goals if you want to take your training to a reasonably high level but otherwise don't worry about them.

jacksonpt

Don't over complicate it. You've made great progress so far, just keep going.

HR zones are HUGELY general, and in reality can vary greatly person to person. Also, they are really only beneficial to people with specific training goals/needs. The average person looking to lose some weight and improve their health is FAR better served by giving their workouts 100% than by worrying about zones.

MeanderingMammal

Zone training has value for serious athletes looking at performance improvement. It's of very limited value for weight loss goals. While the theory is reasonable in practice the difference between the fat loss zone and the aerobic zone is insignificant for fat loss.

You get more from a large calorie expenditure.

Note also that zone training theory isn't relevant for most of what you describe anyway. Squash, HIIT and resistance are all anaerobic activities, with low cal expenditures.

scottb81

Agree with everything posted above. Additionally, at your age 140 is a very good HR to exercise at for any fitness goal.