Very Interesting Read On Fat Burn and Heart Rate

[Marky_Mark]

Check this out. I just found this so thought id share it. Great Web Site too.

https://blog.myfitnesspal.com/how-target-your-heart-rate-get-into-the-fat-burning-zone/

Good Luck,

Mark

[Dominique]

Well, I think there’s some confusion between spending time in the "fat-burning" zone and actually losing fat. You can spend all the time you want in the fat-burning zone and lose no fat at all. The oppposite is true: you can spend no time at all in the fat-burning zone and yet lose fat. Fat loss is determined by the overall energy balance, not by the time spent in various HR zones.

[Bill_k]

So fitbit is wrong?

[Dominique]

Why would Fitbit be wrong? When you create a plan aimed at losing weight, Fitbit wants you to have a caloric deficit that matches the pace at which you’d like to lose weight. Fitbit doesn’t say you need to spend x amount of time in the fat burn zone.

Here is the definition of the fat burn zone from the relevant help article: 

"Fat burn zone, which means your heart rate is 50 to 69% of maximum, is the low-to-medium intensity exercise zone and may be a good place to start for those new to exercise. It’s called the fat burn zone because a higher percentage of calories are burned from fat, but the total calorie burn rate is lower."

Like MyFitnessPal, Fitbit does have a blog with guest posts such as "Get in the Zone: How to Burn Fat Fast with Target Heart Rate Training". Such posts reflect the opinion of their writers, not of Fitbit.

[bikerhiker]

I think if you put certain things in context, then you would have a better picture of what is a fat burning zone.

What I see is missing in articles that talks about the Fat Burn Zone (commonly known as Zone 2 HR) is that, we need to establish a base of reference.  So what base of reference is that is not mentioned in the article(s)?  It is the "Resting Heart Heart" or known as RHR.  So what is Resting Heart Heart and why is it important in establishing a base of reference in relationship with your Fat Burn Zone?  

First of all, your resting heart rate is a measurement of how many times your heart beats per minute when you are completely at rest.  Think of it as you have woken up in bed before you get out of bed or even do any exercise!  That is your RHR.  Now most people have a RHR between 60-100 bpm.  Athletes and people who had exercised all their lives have a much lower RHR of about 40bpm.  Mine is about 38bpm.  Obviously, the lower your RHR the better your cardiovascular health and the more efficient your heart works in any activities you do. 

Now the bad news.  Research from Fitbit shows that the average resting heart rate in the United States is pretty high and both US and Singapore had the highest average RHR of 65.9 bpm or 66bpm.  Only Italy had the lowest @ 61.8 bpm.  All of these data come from the watches you wear and the data collected by Fitbit as you sync your watches.  So what are the implications of this then?  If most people's resting heart heart is between 62 to 66bpm and that's the best case scenario, then if you take someone who is 35 years old and using the 220-35 formula gets you 185 max HR.  So between 50-69% fat burn zone, the 35 year old HR has to do his/her workout between 92.5 bpm to 127.7bpm, but most people's max HR is usually about 10bpm lower than the formula.  So the best case scenario for this 35 year old's Zone HR would be between 82.5bpm to 117.7bpm.  So if this 35 year old starts out with a resting heart rate of 62 to 66bpm (best case scenario), then even after waking and you start making breakfast without even doing any exercises, you are and can even exceed the Fat Burn Zone.  And because the burn rate is much slower than at higher heart rate zones, this means you'll have to do everything including walking and working in your office at a very slow glacial pace plus at a much longer period of time to even take advantage of the effect of fat burning.

Now, if you start with a much LOWER RHR like me, then of course, I have a much better head start than most you so when I walk, climb stairs at a reasonable pace and work at a normal rate (no need to slow down like those with a higher RHR); I can easily be in this range for a very long time like 8 hours in a day and then if I get a good night deep sleep of 8 hours, then that fasting period allows me to burn fat as my energy source too.  But that only works for people who are athletes and are very fit people.  People you see in the Olympics who are very fit and thin.  Now watch your local amateur runs or any exercise activities; are these people as fit and thin as what you see with professional athletes?  The answer is mostly a NO.  They are mostly not and the reason is that, they were fed with half-truths.  It's true that if you are really fit and your body is working properly, the fat burn zone is real.  But that came out from a Suzuki research on Elite athletes.  If you're not an elite athlete, then following an energy balance approach would be better than with a Fat Burn zone.