I recently switched from a FR305 to a FR310XT and have noticed a major change in the calorie metrics. As an example same route, same avg speed, same distance, time, avg HR (4:45 145KM, 137BPM) the ride with the FR305 showed a little over 4000 calories burned. I’ll admit it sounds high but with the FR310XT it shows just under 2300. That is an awefully big swing. Are either of these devices accurate?
In short…no. One of them is probably more accurate than the other, but they only calculate based on speed (regardless of whether or not you have a HR monitor on or not) and not effort/heart rate/etc. But unless you only weigh like 100 pounds, youre probably closer to the 4000 for a 4:45 ride
I’ve found it’s best to ignore the calorie function on any Garmin product. Otherwise you’ll be tempted to eat a large pizza and gallon of ice cream every time you walk to the garage to pump up your bike tires. Not accurate at all to say the least (IMHO).
My Garmin calorie counting is also useless. I weigh 180 and rode 3 hours yesterday averaging 256W with over 3000 feet of climbing and it said I burned 1287 calories.
I recently switched from a FR305 to a FR310XT and have noticed a major change in the calorie metrics. As an example same route, same avg speed, same distance, time, avg HR (4:45 145KM, 137BPM) the ride with the FR305 showed a little over 4000 calories burned. I’ll admit it sounds high but with the FR310XT it shows just under 2300. That is an awefully big swing. Are either of these devices accurate?
It all depends on how exactly you’re measuring it and if you’ve got it configured. No method out there today is perfect. Here’s the low-down on how each Garmin watch works calorie wise and further, within each watch which variations there are for measuring calories:
http://www.dcrainmaker.com/2010/11/how-calorie-measurement-works-on-garmin.html
From a 310XT perspective only, the difference between the results w/ and w/o HR are pretty dramatic. The calculation w/o HR just based on speed and distance I think is pretty worthless. Since I usually wear my HR I haven’t really done an apples to apples comparison but anecdotally I would say that the calculation w/ HR is about 40% lower for me based on perceived effort and time.
I find that using the ‘Power - KiloJoules’ reading to be much more accurate than the calories reading.
I find that using the ‘Power - KiloJoules’ reading to be much more accurate than the calories reading.
Indeed, although you have to make an assumption regarding your own metabolic and biomechanical efficiency this is really the only accurate way of measuring energy expenditure.
So, assuming you have a 310XT and a PowerTap. And, assuming you input the data correctly when you set up your 310XT (weight, fitness level, etc…) and you always use the HR strap (I actually use the Polar WearLink+ strap with the Garmin transmitter that you recommended. But, it doesn’t look like that makes a difference.), it’s going to use the Firstbeat Algorythm (1st Gen) for both running & biking, correct?
Do you happen to know how accurate that configuration is?
So, assuming you have a 310XT and a PowerTap. And, assuming you input the data correctly when you set up your 310XT (weight, fitness level, etc…) and you always use the HR strap (I actually use the Polar WearLink+ strap with the Garmin transmitter that you recommended. But, it doesn’t look like that makes a difference.), it’s going to use the Firstbeat Algorythm (1st Gen) for both running & biking, correct?
Do you happen to know how accurate that configuration is?
Correct.
As far as accuracy goes - Firstbeat claims it’s within 10%. Here’s a full document from them on it:
So where does the LEAF data fit into all of this? I thought on the newer Garmins when you import the LEAF data it added zones and RMR data. On mine the calories burned changes about 35% less after importing the data.
-Jeff