More Number Weirdness

This morning's workout was on the elliptical. Talk about a wide variety of numbers for calories burned, during a 50 minute session, keeping my heart rate between 135 and 145.

Precor Elliptical (with my heart rate signal, weight entered, and age entered): 850 calories

Polar FT-7 HRM: 540 calories

SparkPeople: 1058 calories

Seriously!?!?!

Now, before anybody thinks I'm getting hung up on numbers, I'm not. I'm just a geek, and wonder why the numbers vary so much. I tend to think the real number lies somewhere above what the Polar is telling me, but not much more, maybe 10% more. Each system has it's own limitations. I think the Polar would be the most accurate IF it were also taking into account my BF%. But, now that I think about it, it may be worse. I'm a 350 lb guy right now. If I were this weight but 20% body fat, my lean body mass would be somewhere around 280, vs the 37% body fat that I actually am and my lean body mass is around 220. Which engine burns more fuel? The 220 or the 280? Obviously the 280. None of these systems asks me my body fat %, and are probably making assumptions to arrive at a number. I'm going to keep digging into this.

Not that any of this matters anyway if I'm not tracking my calories - which I have done a really bad job at lately. Must resolve to do better at that. Usually if I'm not tracking my calories, it means I'm not eating right.

In the end, all that matters is moving more and eating right. These number tools are fun to play with, but none of it matters unless you are doing those two things.

Going by the numbers

I finally got my HRM monitor!! I happened to be looking in the classifieds over the weekend, and found a guy who had just posted the exact Polar FT-7 HRM I was looking for. Brand new, only opened the package, for $40 less than I could get it online. Called him immediately and went to his house Sat night and got it. Wahoo!

I fiddled with the thing on Sunday. Got all my stats put in. Layed there in bed for 10 minutes doing nothing trying to determine my resting heart rate. It was right around 70. True resting heart rate should be taken first thing in the am though. But in that 10 minutes I layed there, it said that I burned 30 calories - doing absolutely nothing. If I extrapolate that out over an hour, it's 180 calories in an hour. If I take it further to 24 hours, it would mean that I burned 4320 calories in a 24 hour period. Huh? By all other accounts my BMR is 2500-3000 calories per day(not including exercise). So, I don't where the discrepancy is, but I found that interesting.

I was a dope again over the weekend, and stayed up way too late watching Season 3 of 24 (curse you Netflix!). Hence, no gym on Monday. Today, however, I made it. I hit the treadmill with my new HRM on and ready to go. The treadmill immediately picked up the signal from my transmitter (yes!). Today's goal was to keep my heart rate between 135 and 145 bpm. For me this means alternating between walking and light jogging. My workout time was 50 minutes, and I covered about 3.25 miles. I can cover that distance faster, but my heart rate goes a lot higher if I do, and I'm trying to keep it in the 'Fat Burning Zone'.

Here's where it get's interesting. I had put my weight and age into the treadmill like I always do. At the end of my workout, the treadmill told me that I had burned 669 calories. My FT-7 however, told me that I had burned 554 calories. When I put the activity into Sparkpeople, it told me that I had burned 470 calories. So, going by the numbers, how many calories did I actually burn in my workout? Being the engineer that I am, I'm going with the average, the number in the middle, the 554.

I will keep going with the FT-7. I need a bigger chest strap. The one that it comes with does not fit my 52 in chest. Luckily I can order one. This will be an interesting experiment as I keep going.