Hi
Recently I’ve been using a heart rate monitor. After my workouts I check my total calories burned and percent from fat. I understand that 35% is low while 50-60% is more diserable.
Yesterday I rode my stationary bike for one hour with an average heart rate of 125 (which is the fat burning zone avg for my age of 39 y/o). I would have thought that I would have been in the 50-60% from fat range but I was at 35%. Any advice?
Thanks,
KraigY
everything I have read says that low rate cardio is just time wasted.
You are better off doing high rate cardio for half the time.
125 isn’t even breaking a sweat… I’m 40 and I tend to aim for 150/160bpm on the cardio machines… for 20-30 mins at a time.
It is absolutely impossible to measure how many calories the body uses during a certain workout with a heart rate monitor, let alone determine from what source the burned calories came. It’s not even an educated guess, you could also roll dice or flip some coins to determine a random number.
Furthermore, the process of regeneration often uses twice or more the amount of calories than the actual workout over the period of ~36-48 hours, this is especially true for high intensity workouts and resistance training (lifting).
First thing you probably want to do is understand that you don’t reduce bodyfat by actually burning fat as an caloric energy source. The body converts any type of food into fat anyway as long you are eating more calories (from any source) than you are using.
So what you want to do most likely is to burn as many calories as possible in the shortest amount of time. In that case, any kind of high intensity workout, e.g. HIIT or weightlifting (optimal would be a combination of both) is vastly superior to any kind of low heartrate steady cardio.
Another important aspect would be that your appearance (body composition etc) is a function of your eating habits, not so much of your training. You cannot ‘outtrain’ a bad diet.
I would start reading those wonderful articles available for free on this site, esp by Dr. John Berardi & David Barr
EDIT:some real bad spelling/grammar
In my experience, a heart rate monitor is quite accurate in determining the calories spend during training. I checked my Polar several times during interval and endurance training on a stationary bike (Johnson) and the Polars result were often within a 1% range of what the Johnson indicated.
I would estimate a margin of error of about 10% for both though.
The Polar is used during weight training sessions also, but accuracy is probably lower then.
The Polar gives a guestimate on the percentage from fat and it is usually between 50-60%. The higher the hart rate, the lower the percentage. So it’s a surprise that yours is so low, especially with the low heart rate? Are you sure it is the percentage of fat, and not from carbo-hydrates?
Anyway, while more intense training sessions yield more results, it’s not uncommon to perform “recuperation training” for about an hour with low heart rate the day after a session that is expected to cause DOMS. The idea is that the recuperation training brings blood to the muscles and reduces DOMS.
But, like Slamdog and Petrichor say, this shouldn’t be the bulk of your training. I like to do these on off days and don’t log them.
[quote]Wreckless wrote:
In my experience, a heart rate monitor is quite accurate in determining the calories spend during training. I checked my Polar several times during interval and endurance training on a stationary bike (Johnson) and the Polars result were often within a 1% range of what the Johnson indicated.
I would estimate a margin of error of about 10% for both though.[…][/quote]
Yea, because they all use the exact same mathematical model established during the 60s.
same with bodyfat% measurements through any kind of impedance scale, the coefficients were taken some 50 years ago and since then, all people have been doing is copying each other.
I think there was even an article about that subject up here some time ago 
Only real way to determine your caloric expenditure is through measurement of your exhaled CO2, a process thats pretty lavish and uncomfortable (involves you breathing through a mask which covers your whole nose & mouth with an tube running along the ceiling attached to it during your whole workout)
And even that won’t get the calories burned because of the elevated base metabolic rate, unless you spend like 2 days with that mask on…