[GottaRun]

My friend and I both have a Garmin 205 that we wear when we run. We run together pretty much side by side, so when we compare our histories on the Garmins, we have the same pace and same distance. The only thing that's different is the calories burned, and it's VERY different. I burn more calories than she does, and that's consistently true no matter how far we run. For example, today's run was 5 miles; I burned 938 calories, and she burned 521. So my question is... why? What are the factors that determine how many calories you burn on a run?

 

[sistergoldenhair]

Part of the calories you burn on a run depends on your body mass. Someone with more body mass uses more energy to move that mass (when running and otherwise) and is going to burn more per mile than a person with less mass.<br><br>
Generally the rule of thumb is everyone burns around 100 calories/mile no matter their pace. Plus or minus a bit depending on body mass.<br><br>
Other factors that influence calories burned are a person's metabolic rate, which is partly genetic and partly lifestyle-related.<br><br>
I question how your Garmin came up with 938 for 5 miles. That is 187.6 calories/mile. Are you and your friend very different in body size, age? Are you male or female? (Men burn more calories than woman on average ) Does your Garmin take body composition into consideration (your % lean mass vs. fat mass)?

 

[muzicgrl]

Check what weight you have programmed into it. Mine kept decreasing in Cals burned when I was losing weight and changing it on my garmin. I generally assume 100 cals/mile also.

 

[Hippo]

I'll be nitpicky and suggest that most attempts to count running calories are exercises in fantasy, you should take them all with a large grain of salt unless they involve hooking hoses up to your mouth.<br><br>
Did you ever notice that it's kind of a coincidence that everybody says "100 cal per mile?" That's because implicit in that is "give or take a whole lot, so we'll just round off to the nearest big round number." I also always take issue with the conventional wisdom that "calories burned do not depend on the speed you run." Of course they do! anybody who claims that the calories burned per mile is exactly, precisely the same no matter what speed you run isn't thinking. But where the conventional wisdom comes from is that the change with speed is not any more important than a whole bunch of other things which are hard to measure. Things like running economy vs speed, road/trail surface, temperature, and individual metabolic things all matter at least as much.<br><br>
One other possibility about your Garmin: does it take elevation changes in to the energy calculation? If so, one possibility is that Garmins have some settings that are notorious for wildly exaggerating your elevation gain/loss. If yours has those different settings from your friend's that might account for the difference. Just compare the readings for elevation gain between units to test this hypothesis.

 

[RandMart]

100 calories = 1 mile run = 1 lite beer = 1/2 of something you might enjoy

 

[fox-runr]

true dat.