flr

My GPS-Cyclo-computer shows 4300 Calories consumed during a 81 mile (130 km) road biking with 4300 ft. (1300m) total ascent, almost no wind, 165lb (=75kg) total weight (biker+bike), done in 6 hours and 30 minutes riding time. (average moving speed was about 12 mph = 20km/h ).

Just curious, how much off this estimation of the consumed Calories is? To me looks a bit high.... What a better estimate for consumed Calories would be for above type of ride?

dr_lha

As I've said before in other threads: This way lies madness...

A better way to estimate calories is to get a power meter. Otherwise, it's just guesswork.

Inpd

See the threads I posted a few weeks ago on this very topic but using MapMyRide and Strava. It appears many apps over-estimate. Some would say on purpose, but I think there is probably something more subtle going on like my thread on GPS elevations being weird.

txags92

Riding 12 mph for 6.5 hours, and that amount of climbing, my rough guess would be around 2500-3000 calories based on nothing at all. It would be more useful to know where you were in your HR range to go that speed for that amount of time. If your HR averaged 80% of max for the ride, that 4300 might be a lot closer to correct, but if you were at 60% of max, you are probably looking at something a lot closer to 2000-2500. It is all mostly guess work anyway...even if you use a power meter, you don't know what your own personal efficiency is at turning calories into watts unless you get it tested somehow.

Nachoman

Since I don't have a power meter either, I choose to use the 400 calories per hour guesstimate.

caloso

Seems way high. At least 1500 kcal high.

Tunnelrat81

Those garmin/polar/etc... calorie numbers are why many cyclists/runners etc. wonder why they're not losing the weight they want or expect. The estimates seem to be grossly overstated, so rather than try to make sense of them by arbitrarily calculating percentages or something, I just don't pay attention at all to them. There are plenty of other things worth your time and attention when it comes to riding, things more accurate than a shot in the dark guess at how many calories you've burned.

-Jeremy

JohnJ80

I talked with a nutritionist who works with athletes on nutrition, weight loss and management as part of my training plan. Her guidance was to use the numbers provided by the charts but to use the numbers provided by the bike computer (especially if you enter body weight into it somewhere) if it's available. She says that she has generally found them to be pretty accurate. I don't know if that is because of the ride time vs clock time as measured by the athlete is more accurate or if the computer can figure out the impacts of altitude better. So that's what I do and it seems about right.

J.

Drew Eckhardt 

I looked at what came out of my Garmin Edge 500 based on heart rate after getting a power meter and found that it was always high except on hard workouts (intervals at threshold power and beyond - a tempo ride isn't enough).

Typically it's a 10-20% error, although anything with significant cardiac drift produces extreme differences. On two warmer weather rides it reported 75% (2572 Calories, 1467 kilojoules) and 80% (1103 Calories, 613 kilojoules) high where 1 kj = 0.95 to 1.2 Calories at typical cycling metabolic efficiencies with 1 kj = 1 C an approximation unlikely to over-estimate.

After the last firmware update it switched to using kilojoules with a power meter but no heart rate strap; although before that it fell back to some sort of guess which was farther off.

JohnJ80

I'm using cyclemeter on my iPhone. Her thought was that she thought it looked pretty accurate after she did some calculations. For my training regime, she has me logging all of my nutrition and rides in detail. So, I guess for me, it works.

J.

kingfishr

I did a 133km group ride on Mallorca a few weeks ago, 80kg total weight, 20km/h 1100M elevation gain, 6:32, Garmin Connect makes it 2084 calories based on 127 watts avg power (Strava says 2749). So I would agree your numbers seem a bit high. A similar group ride at 30kmh, 188watts avg and 1250M elevation was only 2347calories on Garmin Connect and 2832 on Strava...

Drew Eckhardt 

It's probably high by at least 30-50%

I'm 5'10", 138 pounds in great cycling shape, 150 pounds when thin by normal people standards. I still ride a 20 pound bike which becomes 22 with one water bottle averaging half-empty for a 160 pound total. Currently I have a 210W threshold power; where 195W is not too unpleasant for 1-1.5 hours and good for 19.8 miles in an hour on flat ground interrupted for just 27 seconds by traffic.

Intensities at longer durations are all percentages of threshold power. 140W is a decent 4-hour pace (67%), 120W an easier endurance effort (57%).

To use a relevant example 63.2 miles, 2350 vertical feet, 4:12 elapsed, 3:55 riding, 16.3 MPH 125 Watts average including 0W at stops, 1897 kj, 1806 - 2258 Calories over the 20-25% efficiency range observed in cyclists (multiply by 1 Calorie / 4.2 kj and divide by efficiency of .20 to .25)

120W * 6.5 hours * 3600 seconds = 2808kj, 2674 - 3343 Calories.

tarwheel 

For comparison sake, I rode 86.4 miles Sunday at a 15.5 mph pace, on a route that had about 3,000 feet vertical elevation gain. Total riding time was 5:35, and I weigh about 175 lbs. My LoseIt! app estimated that I burned 4,155 calories. I have found LoseIt's calorie estimates to be reasonably accurate, and lost 30 lbs using them to track my calorie consumption and burn.

cellery

To me it is more important to determine mean weight gain or loss over a given week. If I come out even, I eat the same. If I gained a couple lbs over a week's worth of weigh ins I might increase salads and decrease pizza; if there was sudden dramatic weight loss - then I'm probably not drinking enough water. You get the idea.

Those incredible calorie burn numbers on your HRM, cyclocomputer, garmin, etc. are hooey. When I rode from Phoenix to Tucson my HRM said around 4800 calories burned; Strava said something almost a thousand calories less. That's a huge difference - if they're off by anywhere from 10-20%, where does that leave you in trying to lose or maintain a weight range? Even a small percentage of error makes those numbers effectively meaningless; this is why I stopped wearing my polar watch - the data just isn't useful unless it's exact.

StanSeven

Next time you see her, ask how she did her calculations. I'm interested.

Willbird

I am pretty sure there is no OTHER thing that will wrap people as tightly around the axle as calories burned per hour doing.....................anything really.

You can find any number you want for that ride, from the 400 per hour a lot of people use. and the ones that I know who do LOSE when they are aiming for a calorie deficit. Or I'm pretty sure you could find and ap that would credit you 1500 calories an hour.

Personally I never dig into calories like that very much, I did decide to use 100 a day, and one day a week dig a little deeper. I have data for over a year of eating mostly at a -7000 deficit a week, with 5-7 hours of riding a week, that showed maybe an extra 1750-3500 being expended, showing up as 2.5-3.0 lbs average loss instead of the 2 I was eating to achieve.

Bill

StanSeven

Hmmm. It might make more sense if I referened the correct post. I meant to use the post of JohnJ80

RShantz

I've got a related question. I road on Saturday and my power meter as reported from garminconnect said that I burned 2,900 calories but when imported into Strava the calories increased to 3,300 on Strava's site. I'm not into looking at the calories but the difference confuses me. I always assumed the PM was the most accurate reading for calories & don't know why Strave bumped up the amount?

Any thoughts?

Heathpack 

I did a ride on Sat that was 114 miles/11000 ft elevation gain, 12.7 mph, 8:51 pedaling time.

I have a power meter, rode the first 3.5 hours of the ride at 85% FTP (strong effort) then the rest at around 67% FTP (medium-ish to slightly weak effort, I was getting behind on nutrition, getting bonky). My power output for the entire ride was at around 70% FTP.

I weight 140 pounds. Burned 4300 calories on the ride. Even with the power meter, however, that 4300 number is not exact, it also depends on your metabolic efficiency.

So for me, it worked out to around 475 cal/hr, or 3.4 cal/pound body weight/hr.

Important variables are your body weight and how intensely you're working.

Machka 

These days I've been doing this calculation ...

100 cal for every 5 km of cycling.

So 130 km / 5 = 26 * 100 = 2600 calories burned.

That's the calculation I've been using in MyFitnessPal when I record my exercise ... and I've been quite successfully losing weight.

bobones

10 calories per minute for cycling at a brisk (tempo) pace is a pretty reasonable approximation.

rm -rf

This previous thread has some good comments: Does Cycling Really Burn Up THAT many calories

A simple rule of 25-30 calories per mile (or Machka's 200cal per 10 km = 32 cal per mile) seems to work for most riders. Or, if you can estimate watts: watts x hours x 3.6 is pretty close.

That seems reasonable if you keep riding at a brisk pace. For example, a flat road 18 mph is .3 miles per minute. So that's 33 cal per mile.

bobones

I did a 34 mile ride with 2500ft of climbing in 2 hours.

My Garmin with HRM says I burned 1136 calories (this is what I go on).
Strava says I burned 1636.
LoseIt would say 1729.

The 10 calories per minute estimate gives 1200
25-30 calories per mile gives 850 - 1020
32 calories per mile gives 1088
200w (Strava estimate) x 2 x 3.6 gives 1440

I've read that a Garmin with HRM uses the FirstBeat algorithm to calculate calorie burn and it's meant to be pretty decent.

Willbird

I just do not see how the algorithm can compare two cyclists the same height,weight, age, and HR, and know the fitness level of either cyclist ?

to begin with maximum HR and LTHR vary wildly individual to individual.

bruce19

I'm pretty much doing the same although if it's been a particularly fast or hilly ride I will go up to 15/min. I base this on a formula I found in some cyclist training book. It supposedly takes into account body weight and speed and I totally accept this as a "ballpark" figure.