Housework Cals - the pitfalls

Ange_

Hi.

I just thought i'd share some thing i have recently learnt as i think it might help some other people too.
Now i know there is a big debate about whether or not to count things like housework, gardening, moving boxes when moving house etc as exercise.
I'd always thought, well if it is something unusual, not part of my regular daily activity, and if i wore my HRM so i could measure it accurately i'd count it. I know a lot of you all do the same.

Then i started a big renovating project with my BF which we were doing on the weekends. I diligently wore my HRM for this work, which took most of the day and logged it as calories. I didn't always eat them all back, but often did as i didn't have access to good food during this time, but didn't feel guilty as according to my HRM i'd earned them from all the renovating work.

Then i hit a big plateau. I lost nothing, gained nothing and coudn't work out exactly why.

Then i got a fitbit and stopped using my HRM for things other than traditional exercise and I started loosing weight again. I noticed that the fitbit added way less calories that i could eat back on renovating days than i'd be adding using my HRM. So i did a bit of research into this. Turns out a HRM DOES NOT SUBTRACT YOUR BMR FROM THE RESULT.

Incase you don't know what that is, your BMR is the amount of calories your body burns just to keep you alive, that you would burn even if you were in a coma for the day and didn't move.

If you do half an hour of running or working out at the gym then chances are that the afterburn effect probably will make up for the fact that you haven't subtracted your BMR for that period of time. The afterburn effect is that your metabolic rate is increased for a period of time after intensive exercise. So probably nothing to worry there.

The problem though comes if you are doing like i was, a very long, low intensity activity like renovating a house, cleaning, gardening etc. I imagine hiking could also have this issue too as an activity done over a long period of time.
I worked out my BRM was 66cals a hour. So for 5 hours of moving i would have overestimated the calorie burn by 330 calories!
No wonder i hit a plateau!

Quite frankly i'm annoyed at the makers of HRMs that they don't subtract your BMR and just give to a result of the extra calories you've burnt from your exercise. They generally have all the personal information already in them they'd need to work this out.
The reality is though that they don't , and that is all the major brands like Polar and Suunto etc. Assume if your watch doesn't specifically say it minuses your BMR that they don't because this seems to be the industry standard.

So that means there are 4 choices available.

Either:

1. don't log calories burnt through from non traditional exercise activities. The problem with this is though that you could put yourself in danger from eating too few calories if you have a period of time where you are doing a lot of these activities which you aren't eating back.

2. Adjust your activity level setting on a day to day basis any time your activity level varies. For example have weekend setting and a weekday setting. This is a pain though to do, and the MFP estimates for activity level settings isn't necessarily going to be all that accurate and neither is your ability to estimate.

3. Wear your HRM when you do these activities but subtract your BMR for that period of time from the result. This is the most accurate method. I'll explain how to work out your BMR per hour soon.

4. Buy a device specifically designed to track your activity level each day. the Fitbit is fantastic for this. I am a huge fan. There are other things too such as a body bug. Fitbit syncs with MFP which is just perfect. Once it is set up you don't need to do anything and just eat what MFP says to eat. You may still want a HRM though for your traditional exercise especially if it is something that isn't running or walking such as an exercise video or exercise bike. But the system is well set up that you can use a combination of a HRM and the fitbit to get the most accurate results.


Ok how to work out your BMR per hour:

http://www.myfitnesspal.com/tools/bmr-calculator

Go to the BMR calculator above.
Put in your details. This will give you your BMR for 24hrs. So now to work it out per hour, then just divide this number by 24!
Easy.

In case maths isn't your thing. Here is my example.

My BMR according to the calculator is 1599 calories.
So my BMR per hour is 1599/24 = 66.6

So say i did some gardening for 3 hours and 45 mins. My HRM says i burnt 500 calories. What i actually burnt onto of my BMR then (which is the amount i put into MFP as cardo) is:
66.6 x 3.75 = 250 (rounded up).
500 - 250 = 250 calories

So see, if i hadn't done that calculation i might have thought i burnt twice as many calories as i had!

By the way as i said i don't think this is necessary for intensive exercise, even if you are working out for a whole hour as the after-burn effect probably negates it.

Hope that helps. Please nobody berate people who chose to set their MFP activity level as sedentary and then add on calories for daily activities such as cleaning. It is a personal choice. I'm just trying to help people who choose to do so not make the mistake i did myself.

Fitness4Paul

I love my fitbit. I'm set to sedentary for my office job but get pretty active when I'm around my kids. The automatically compensates for the times of increased activity. I take it off for workouts and log my excercise accordingly.

Azdak

Why would you be "annoyed" at the HRM manufacturers because you are using their product in a way that it was not intended to be used?

Ange_

Why would you be "annoyed" at the HRM manufacturers because you are using their product in a way that it was not intended to be used?

well for one thing the HRM manufacturers don't really explain what i is that their numbers really mean. it took some serious investigating to find out. On other websites, and where i found people had actually had to phone up the manufacturers to find out.

And secondly there is nothing saying that only short high intensity exercises are suitable for HRM use. As i explained it can be used for anything if you take into account BMR. Who gets to decide what is and isn't exercise anyway?
This applies to long walks. Everyone would agree a long walk is exercise. yet this issue of overestimating apply to this activity.
I believe all my HRM says is that it isn't suitable for medical applications.

ettaterrell

great info!! Thanks! But alittle bumbed too now because I just thought about it and nt brm is 120 for 1 hr or 60 for 30 mins. If I work out for 30 min and only burn 160 cals then I need to take 60 from that only giving me a work out of 100... ugh. But it makes senice.