The Chances

How a 250+ Pound Couch Potato Got Healthy

Thursday, December 04, 2008

Midweek Run - 6.2 miles

It's after midnight. YEAH! IT'S AFTER MIDNIGHT! I'll be paying for this at 4:30 when the alarm goes off.

Anyway, today's run went well. In the name of experimentation, I ran without the HRM strap.

Here be splyts.

Mile 1: 8:28.49
Mile 2: 8:24.13
Mile 3: 8:41.95
Mile 4: 8:40.49
Mile 5: 9:07.48
Mile 6: 8:45.11
.20 Mi: 1:44.19 (8:48/mi)

6.2 miles, 53:51.41, 8:41/mi, 776 calories burned.

Or was it?

On Tuesday I ran the same route, at just about the same exact pace, in the same time within 5 seconds. The thing is, I wore the strap, and you know what the calories burned was? 778 calories! Today was 776.

The evidence obviously points to the fact that the Garmin Forerunner 305, as cool as it might be, doesn't even bother to use the HRM strap for calculating calories burned. It calculates it the same way an elliptical machine or treadmill calculates, which is using age, weight, time, and distance.

The Garmin 50 is the same way. I tried wearing it in the gym during a weight workout to not only plot my heart rate over time, but calculate calories burned as well. The only problem was, since I wasn't using the foot pod at the time, nothing was recorded for calories burned!

This is mind numbingly stupid. Apparently all the Garmin units are this way, even the Forerunner 405. So here you have, in the case of the 405, a $299 unit that can't even show accurate calories burned!

There is hope, however. Since the Forerunner keeps all the data, there's a running heart rate for every reading the thing makes. Garmin Training Center doesn't let you do anything with that data, but SportTracks has plugin capabilities. While it doesn't have this capability, it would seem to me that it would be a simple matter to take that heart rate data, plug it into a calories burned formula for each GPS or foot pod reading, then output the more accurate number at the end.

In the meantime, it's back to the Reebok HRM that I bought for $20 on While it doesn't output to the computer, it does calculate calories burned based on heart rate, not time & distance.

Oh, and another thing: my thigh muscle's been twitching for the last hour. I'm going to bed now.


Chad in the AZ Desert said...

The reality is that even with units that use HR as part of the calorie calculations, it's still an estimation of the actual calories burned. Nothing short of a laboratory treadmill built to measure your actual wattage of effort along with about 50 wires monitoring all of your body systems is going to give you an 'accurate' measure of calories burned. Even the HR measuring on the Reebok is using an algoritum to arrive at calories burned. It just happens to incorporate HR into it.

Besides, too much data takes all of the fun out of it. ;-)

Greg said...

I much prefer something that takes some sort of reading off my body to something that doesn't even take effort into consideration! I mean come on, if I drive 26.2 miles, can I say I burned 5000 calories?

Marcy said...

Ok wait a minute . . .I'm still trying to get over teh part where you said "It's midnight" and then something about a "4:30am wakeup??!? What tha?!? You're insane ;-)

Darrell said...

You'll drive yourself crazy with trying to sync all the gadgets and calculations. ;-) Nice runs the last couple of days.