Garmin: Calories vs heart rate

[Brucer]

Using a Garmin 500, I ride 30 miles wearing a heart rate monitor, I burn about 335 calories. Without the monitor, I burn 1200 calories, according to the Garmin. How do I reconcile the discrepancy? In other words, ***?

[Louis]

How do I reconcile the discrepancy?

It probably uses a different algorithm to calculate the calories burned, depending on the inputs available to it. You'd think that more data would equal a better estimate, but 335 calories for 30 miles seems way low to me. Of course it depends on the difficulty of the route, your speed, etc.

In general 10 calories per minute is a good baseline for cycling.

[DRietz]

It probably uses a different algorithm to calculate the calories burned, depending on the inputs available to it. You'd think that more data would equal a better estimate, but 335 calories for 30 miles seems way low to me. Of course it depends on the difficulty of the route, your speed, etc.

In general 10 calories per minute is a good baseline for cycling.

I don't know, what was the max heart rate during the ride? If he was just out there spinning, I could see 335 calories being the deficit.

[Louis]

Calories burned will correlate better to average HR, not max.

[CNY rider]

Leave them both home and focus on enjoying your bike ride.

[MattTuck]

300 cals seems very low for 30 miles, unless you had a 20mph tail wind the whole time and were riding on your own (no drafting)!


Calorie Chart (http://www.nutristrategy.com/fitness/cycling.htm)


Obviously, each person has slightly different body chemistry, but this is a good average and is pretty similar to other calorie charts I've seen.

For what it's worth, the garmin connect website usually has me burning significantly more calories than strava's reported calories. Not sure what the exact reason is, but it is clearly in the algorithm they use to calculate it. I'd stick to an average (like the chart I linked) until you have good reason to trust a point estimate that is significantly different.

[oldpotatoe]

Leave them both home and focus on enjoying your bike ride.

Yep-

[wasfast]

I've experimented a fair bit with my Garmin 500. It estimates low (only using HR in my case) across the board. One thing to check is the settings for calories in the menus as well as weight, height etc. They use an algorthim from FirstBeat (http://www.firstbeat.fi/) and the settings can have a big impact on the readings. The calories expended are only for use with heartrate.

I've also had VO2max test done that calculates your expenditure. It says 800 kcals/hr for my 180lbs at Aet. Even 600 kcals/hr is conservative if you're riding a decent intensity for estimating purposes.

[shovelhd]

Garmin calories are not accurate.

[oldpotatoe]

Garmin calories are not accurate.

Maybe is you dunked it in milk first....

[shovelhd]

They trend high, so that would have to be skim.

[wc1934]

For a 30 mile ride - 1200 seems about right (at least in comparison to what my numbers look like).

[bigbill]

My Garmin said I burned 10,400 calories during the 2008 STP. That's around 1000 an hour for me at 220# averaging 20mph. Sounded about right. For shorter rides, I don't put much into the calories.

[Brucer]

Thanks. I checked the calorie count website, and it corresponds to a more reasonable level. I'm not a fanatic about using the Garmin, but in Toronto these days I ride the rollers indoors, and I like to get my heart rate up so I don't turn into a three-toed tree sloth by April. I try to ride about 20-25 miles at an average of 25 mph at a cadence of about 90-95 rpm. (Mostly I try to stay on the rollers without crashing through the back door. But this sounds more impressive.) Anyway, I'm glad to hear that I'm not the only one who notices a discrepancy in the Garmin calorie register.