burned calories estimation
 

Hi all!

I am a girl in 20s and I'm trying to lose weight. Is it true that I burn roughly 1.000 calories biking 25 miles? I generally get around 10-12 miles per hour on a flat surface and I weigh 185 lbs. I'd like to know your opinion.

Thanx a lot!

It depends on a number of things, but 600-800 should be closer to reality.

Based on the standard accepted chart (published by UW-Madison some years ago), 1000 probably isn't too far off. You may want to visit the Clydes/Athenas forum. There are a number of participants there who have logged their mileage, weight, and food over long periods of time and could share their experience regarding the accuracy of those charts.

Sort of roughly ... you'll burn approx. 500 calories per hour.

500 calories per hour for sustained effort. Cruising along, likely less. My cateye v3 and endomondo have vastly different concepts of calory burn. Anything that monitors hear rate is likely to
be more accurate though.

Yep. Agree. That's close and accurate enough...as long as your breathing is elevated for the duration.

I burn 500/hour or a bit more if it's a sustained real effort. Can do 600 for a couple of hours if it's nonstop and uphill. But the OP specifies speed of 10-12 mph, which is pretty slow and low-effort (unless it's on something like a beach cruiser.)

Correct. Speed is irrelevant. It's the level of effort. If you're overweight and out of shape, maintaining a 12 mph avg could be a significant and adequate level of effort, easiest judged by how hard you're breathing. A moderate exercise level would be elevated breathing but still able to talk, but not sing, and working up a light sweat after 10 min.

No. You're looking at 40W for 2 hours or 30W for 2.5 hours which doesn't net more than 300 Calories at typical cycling efficiencies.

500 calories an hour is 140W and enough for a representative 5'10" male cyclist totaling 220 pounds with his bike to average 18 MPH riding on a road bike atop the brake hoods.

(.4 m^2 Sd, .760 Cd, .004 CRR)

I'm pretty sure that even my 70 year old mother-in-law can do better than 40W for two hours, and, as far as I know, she never sat on a bicycle in my lifetime (she'd need training wheels, though.) Yes, it takes somewhere in the vicinity of 40W to maintain 12 mph on a road bike on the hoods on flat road. I would conclude that the OP does not have a road bike, and/or reports the total average including traffic lights, and/or there are some hills along the way.

If we assume that the OP can maintain 120W moving average on an upright hybrid/MTB, that gives me moving speed of 14.5 mph. Assuming 10 minutes per hour at traffic lights, total speed is down to 12. It takes 1.72 hours and 800 to 900 calories to cover 25 miles.

^^^This. Working on 25/30kcal per mile is probably realistic. Certainly more realistic than trying to guess at kcal per hour, which is entirely dependent on how hard you ride.

If riding 25 miles burned 1000 calories, I'd be a pencil right now, instead of still 10 lbs overweight.....

Whatever charts/online calcs/et al say....figure half or less, and you might be in the ballpark.

Something to consider: It's not juist the calories you burn while doing something....but the "afterburn" that can make a huge difference. [Afterburn is when your metabolism is elevated for an extended period after doing something, which causes you to burn more calories even when doing nothing)

A 4 minute Tabata drill [if done properly- NOT like these Bozos on youtube who can talk while doing it!] may burn 300 calories.....but the afterburn can last for 24-36 hours! In a study I saw recently, they calculated that in total, when taking into effect the actual Tabata drill and the afterburn, those doing Tabata actually burned 750 calories due to the Tabata and it's afterburn- not bad for a 4 minute workout...painful as that 4 minutes can be.

Ridiculously high, I'd suggest. For me to burn 300 kcal in four minutes I'd need to sustain a power output of about 1300 watts for that period. I'm guessing (but it's a very confident guess) that I couldn't sustain that for two seconds. Its more than Mark Cavendish puts out in the final 200 metres of a bunch sprint.

I'd say that figure is too high. I use a similar figure (40 cal/mile) as a reckoning but I weigh more like 250lb and maintain an average of more like 15mph. Some would say my broad brush figure of 40 cal/mile is still too high.

Check out some of the on-line calculators. They seem to suggest that on a flat road in calm conditions, maintaining 15mph at your weight requires 74 watts. That equates to about 17 kcal per mile.

Of course, most roads aren't flat, and the wind blows. But still...

By large using programs like myfitnesspal.com to monitor food and exercise (ESPECIALLY since it is all USER input and not scientific) is largely flawed and unreliable. The only way to get a close to true calorie burn count is to measure and map your heart rate. The following website teaches you the mathematics on how to figure that out.

http://www.livestrong.com/article/46...t-heart-rates/

No, I'm afraid not. If these algorithms worked, then the calorie counts given by heartrate monitors would be accurate, and broadly consistent. In fact, if you use different monitors you will get wildly different results, and that is because they all use different versions of the sort of formula you have linked to, and none of them are accurate - they are all based on a set of assumptions that may or may not apply in the real world.

Thank you all for your answers.

I borrowed my friend's heart rate monitor and went on an hour and 20 minutes bike ride (travelled 17.32 miles) My heart rate monitor said I burned 520 calories. Actually, I did not put my all effort and did not sweat too much. Do you think that it's accurate?

I could be mistaken about the amount of calories initially burned- but don't forget- eight 20-second intervals at 170% of VO2 max, will still be quite significant. Effort is more important than time. But the conclusion was, that those doing the Tabata ended up burning more calories than those who did an hour of regular spinning (The spinners burned a few more calories initially- but over the course of 24 hours, the Tabata group burned more)

I'd say that that is in the ballpark.

Here's another reason why charts and online alculators can't be accurate: As you get fitter/stronger/accustomed to doing an exercise, you burn less calories for the same distance/time.

That sounds like a reasonable estimate; it's about 30 Calories per mile. It's an estimate, not a measurement, but it's probably in the ballpark.

Yes, that sounds accurate.

Sure, and of course one problem is that for every online calculator that suggests I burn 5 calories per mile there's another that suggests I burn 250 calories per mile. With such a wide range I ended up just picking a value that seemed to have a few places suggesting it was about right.

FWIW my 15mph is a moving average speed, so going up hills loses me time that needs to be recovered on the flats, and slowing and restarting at junctions/crossings/lights etc also pulls the average down. When I'm moving on the flats unimpeded I try and maintain 18-20mph for as much of it as possible.

FWIW, I'm male, 33 years old, 207lbs, 6' tall

I rode for 97 minutes today, averaging almost 16mph with a few hills and some wind. Avg heart rate was 150.

myfitnesspal said I burned 1517 calories.
Garmin said I burned 1177 calories
Strava said I burned 774

Strava was still probably a tad high but at least it seems to estimate much more on the conservative side of things.

I don't think so. It takes exactly the same amount of energy to move a fit 200lb athlete 15 miles at 15 mph as it does an unfit 200lb athlete.