Calories burned using a Heart Rate Monitor

bcweisen

So I recently bought a HRM so that I could track calories expended better. Because I am being so specific (ie. anal) in measuring and recording my food intake, the only piece of the puzzle I was guess-timating was exercise. So I have discovered that (for me) MFP under-estimates some things and over-estimates others.

I wore my new HRM to work today so I could get a better idea of how much I actually burn at work. I am a Physical Therapist at a Rehab Center so I have a very active job and because I only work 1-3 days per week, I count it as added exercise on those days rather than upping my activity level.

So in 7.5 hours I burned 2020 kcal according to the HRM. BUT... that obviously includes some calories that MFP already accounted for me burning. My daily goal is set on 1790 with 1.5# loss per week so a 750/day deficit. So MFP plans on me burning 2540 per day. I did some assuming to try and figure this all out.

I assumed that I burn less calories while sleeping. 80 per hour x 10 hours = 800 That leaves 14 hours waking at 125 = 1750
If I burned 2020 in 7.5 hours and subtract the (125 x 7.5) 937.5 = an extra burn of 1082.5 Is this right? Or am I over-estimating this burn?

I'm so confused and that looked really high so I just put down 120 minutes of leisurely walking which is 677. Does anyone else know how to do this better or more specifically?

Newfiedan

most hrms are not accurate for daily burns with regular day to day activities, they are usually only accurate for cal burns when the heart rate is slightly elevated above the norm.

cmriverside

^^Yeah, that. To get an accurate daily burn you need a Body Bugg or similar device. A HRM is not accurate for daily activity.

bcweisen

I specifically bought a HRM for use in exercise and swimming. BodyBugg can't be used in the water nor am I planning to spend that much money. Any idea how I can figure out appropriately my work expenditures?

cmriverside

Okay. That is what they are made to do! Exercise tracking. Once you set it up to your specifications, that is really the best you can do. It isn't a perfect number....much as we want it to be. Just subtract out your regular calories ( like 80 an hour or 60 an hour, whatever you want....it isn't exact.)

Here's a great blog post by someone who is really knowledgeable in the field: http://www.myfitnesspal.com/blog/Azdak/view/the-real-facts-about-hrms-and-calories-what-you-need-to-know-before-purchasing-an-hrm-or-using-one-21472

bcweisen

Thanks... As hard as I try it's still educated guessing. That why I try to log that type of activity on the low side.

Newfiedan

the only hrm that I have found to be pretty darn accurate to date are the sportline watch that has the back sensor on it and the polar ones with the chest strap with the polar one being the most accurate one I have used to date.

cmriverside

I think you'd be better served by upping your activity level to Lightly Active. The description is "Lightly Active: Spend a good part of the day on your feet (e.g. nurse, salesman)."

I'm betting that you do housework and other running around on those other two days, and the difference in calorie allowance is only going to be a couple hundred a day at most.

The HRM is really meant for aerobic activity, not walking at work, or demonstrating exercise for clients. A nurse or salesman would have a little less physical activity for five days - and you would be working a little harder for three days. I'd use that if you aren't already.