How many calories do you burn, realstically?

AmpedCycle said:

Where can I find a reliable source for calculating burnt calories? I get results all over the board on the internet... I need something more concrete.

fitday.comfitday.comOpen ↗

allows you to track calories in and out.

Perhaps you would tell me if the excercise section is detailed enough for you?

Here are the cycling options:

[font=arial]Bicycling, <10 mph, general, leisure, to work for pleasure[/font]

[font=arial]Bicycling, >20 mph,not drafting[/font]

[font=arial]Bicycling, 10-11.9 mph, leisure, slow, light effort[/font]

[font=arial]Bicycling, 12-13.9 mph, leisure, moderate effort[/font]

[font=arial]Bicycling, 14-15.9 mph, racing or leisure, fast vigorous effort[/font]

[font=arial]Bicycling, 16-19 mph, racing/not drafting or >19 mph drafting, very fast, racing general[/font]

[font=arial]Bicycling, BMX or mountain[/font]

[font=arial]Unicycling[/font]

You can pay for and download a better version, but how much better it is I don't know.

AmpedCycle said:

Where can I find a reliable source for calculating burnt calories? I get results all over the board on the internet... I need something more concrete.

i tend to find, having checked a few on-line calculators that they are badly off (maybe by as much as ~ 200 kcal/hr).

if you want a good ball-park figure then you'll need a power meter to look at the energy expended. however, this will still be off (slightly) as you would need to know how efficient you are (and this changes depending on many factors including cadence, terrain, absolute power, environmental conditions etc). you can find out how efficient you are in an ex. physiology lab, but that will only be your efficiency under the conditions tested.

ric

AmpedCycle said:

Where can I find a reliable source for calculating burnt calories? I get results all over the board on the internet... I need something more concrete.

I use a heart rate monitor that calculates calories based on heart rate. You enter your age and weight and it uses an average to give you your caloric output.
The only drawback with the charts, as on Fitday, is that they are based on level riding. 14 mph on the flats is not the same calorie ouput as 14 mph on a steep climb.
Neil

AmpedCycle said:

Where can I find a reliable source for calculating burnt calories? I get results all over the board on the internet... I need something more concrete.

Here's one that's free. Can't vouch for it's accuracy but it was in line with my Polar A5. Can't vouch for it's accuracy either though. Most calorie calculators are very crude estimates as Ric says.

http://www.primusweb.com/cgi-bin/fpc/actcalc.pl

No sign in necessary. Seems to have all the ranges listed as Fitday but you aren't required to log in and receive spam. My only gripe with this one is that 16 - 19 MPH is quite a spread. Too bad they can't break it down a little better. Also, everything over 20 MPH is ranked the same.

Doctor Morbius said:

Here's one that's free. Can't vouch for it's accuracy but it was in line with my Polar A5. Can't vouch for it's accuracy either though. Most calorie calculators are very crude estimates as Ric says.

http://www.primusweb.com/cgi-bin/fpc/actcalc.pl

i've just used the calculator and for 16 - 19 mph it suggests that you expend 1080 kcal/hr. That would be an average power output of ~ 300 W, and is very out. I tend to average ~ 200 W for such a velocity, and that's ~ 700 kcal.

ric

ric_stern/RST said:

i've just used the calculator and for 16 - 19 mph it suggests that you expend 1080 kcal/hr. That would be an average power output of ~ 300 W, and is very out. I tend to average ~ 200 W for such a velocity, and that's ~ 700 kcal.

ric

Had been asking this question myself and started the process recently of monitoring weight change vs calorie intake vs ( miles, time-in-HR-zones, avspeeds,.. cyclecomputer cal estimate ) , usefull as a matter of course whilst reducing BF. .. lots of fun with excell. I've just got Distance data for 5 days ( weight/cals for a lot longer ), hope to compare the above methods ..

.. curious to know if anyone does that, how usefull have they found it .

my powertap records kilojoules produced, which in the end, is about the same as the amount of calories burned. Today's 2.5hr tempo ride burned 2600 calories.

velomanct said:

my powertap records kilojoules produced, which in the end, is about the same as the amount of calories burned. Today's 2.5hr tempo ride burned 2600 calories.

That sounds like a pretty stout tempo pace. Does the Powertap also show your average power output? Guessing it would have to be around 300 watts? How about average speed....around 22 mph?

dhk said:

That sounds like a pretty stout tempo pace. Does the Powertap also show your average power output? Guessing it would have to be around 300 watts? How about average speed....around 22 mph?

Average power would have to be 289 W with those figures.

As for how fast someone would go with that power will depend on their CdA, the environmental and topographical conditions.

ric

dhk said:

That sounds like a pretty stout tempo pace. Does the Powertap also show your average power output? Guessing it would have to be around 300 watts? How about average speed....around 22 mph?

youre close. 23mph average with windy conditions, and rolling roads. i am 6'2" 173lbs. (no aero gear)
I did a 2hr tempo at 322watts average. (tempo pace for me is equal to a 3hr TT) it was such a great ride, by far my best power for tempo. my training has been going so well since I started working with a coach.

I had included my warmup and cooldown, in my previous post.

velomanct said:

youre close. 23mph average with windy conditions, and rolling roads. i am 6'2" 173lbs. (no aero gear)
I did a 2hr tempo at 322watts average. (tempo pace for me is equal to a 3hr TT) it was such a great ride, by far my best power for tempo. my training has been going so well since I started working with a coach.

I had included my warmup and cooldown, in my previous post.

Good God, how do you people sustain these speeds? After a warmup I tried to sustain 20 MPH for as long as I could on my Cyclops Fluid 2 and held it for a whopping 3 minutes before giving up. 🙁 I can't imagine keeping that up for more than 10 minutes regardless of how fit I may become.

By myself, not in groups, I ride a steady 21.5+mph... depending on wind, for the most part, since I live in a relatively flat area. And, I weigh about 165. For the usual 35-40 mile rides that I do, I'm not so sure about calorie calculators because I think I'm more efficient at cycling than the subjects they used in their tests to determine calorie consumption. That's why I'm curious... but I'm also curious because I eat about 4000-4500 calories per day. I had my BMR tested with a CO2 measuring device (that measured % CO2 in my exhalation, and thus, my BMR) that said I expend 1989 kcals/day. Plus, I weight train 3 days per week, and play 30 minutes of basketball every other day. And I'm a student, so go figure! Always moving.
The reason that I want to know calories expended is because I've gained weight in the last few months, and my hunger has increased substantially. So we'll see about how I do in the long run... I'm usually able to estimate my hunger really well, since I've been exercising for a little while, now. Thanks again

ric_stern/RST said:

Average power would have to be 289 W with those figures.

As for how fast someone would go with that power will depend on their CdA, the environmental and topographical conditions.

ric

Ric: Using your estimate that kjoules work equals kcals expended makes the conversion easy: avg kilowatt output (kjoules/sec) x seconds= kcals expended.

Agree on the speed issues; throwing around average speed numbers doesn't reveal much about power output due to all the variables you mention.

Speaking of CdA, I was surprised to see so much variation in pro TT positions last week at the Tour De Georgia TT stage. On the finishing straight, some had the "classic" flat-back position, several had their noses almost on the stem, and then there was Lance, with his relatively high position and arched back.

Doctor Morbius said:

Good God, how do you people sustain these speeds? After a warmup I tried to sustain 20 MPH for as long as I could on my Cyclops Fluid 2 and held it for a whopping 3 minutes before giving up. 🙁 I can't imagine keeping that up for more than 10 minutes regardless of how fit I may become.

Doc, speed on the fluid trainer would be dependent on the resistance setting in the unit; I wouldn't use that to measure anything. Have you tried to test your speed on a flat road in perfect conditions for 10 minutes? If you can you get into and hold a good aero position, you might be surprised at how close you come to that 20 mph.

Don't be discouraged though. Many of us here will never do a 2 hour tempo ride at 322 W...either due to health/fitness issues, genetics, time to train, or advancing age (that's my excuse). You don't have to be a genetically-gifted 30 year old Cat 3 racer to have fun and gain lots of benefits in our sport.

Just checking my records.

I did a fifty mile cycle the other day over an undulating course.

I have a heart rate monitor that gives details of heart rate, average speed, top speed, calories expended.

My average speed was 19.10 miles per hour.
My top speed was 26.1 miles per hour.

Of the 157 minutes cycling, I spent 110 minutes within my aerobic threshold.
47 minutes were over that limit.

My calorie count for that time/distance is 2,123 calories.

limerickman said:

Just checking my records.

I did a fifty mile cycle the other day over an undulating course.

I have a heart rate monitor that gives details of heart rate, average speed, top speed, calories expended.

My average speed was 19.10 miles per hour.
My top speed was 26.1 miles per hour.

Of the 157 minutes cycling, I spent 110 minutes within my aerobic threshold.
47 minutes were over that limit.

My calorie count for that time/distance is 2,123 calories.

Interesting data. If 2123 kcals expended = 2123 kjoules work done, then 2123 kj/9420 seconds = 225 watts average power for your ride. That power estimate seems to be at least in the feasible range, considering your avg speed of 19 mph, real-world variables, and all the other assumptions in your HRM software.

Of course, even if the average power estimate of 225 watts is close, that doesn't really tell how hard a ride it was. You could have been going deep into the red for those 47 minutes over your "threshold" (however that's estimated), which would make for a lot tougher ride than one done at steady output.

dhk said:

... Don't be discouraged though...

Too late, but thanks. I've already switched over to GPP training and have tossed out my cycling goals for this year. 🙁

Will be phasing in some weights this week but will need to experiment around with what works best. Planning supersets with large bodyparts with perhaps some squat thrusts, jumping jacks, pushups and maybe even some wind sprints thrown in for flavor.

When dealt lemons, make lemonade. Right?

dhk said:

Interesting data. If 2123 kcals expended = 2123 kjoules work done, then 2123 kj/9420 seconds = 225 watts average power for your ride. That power estimate seems to be at least in the feasible range, considering your avg speed of 19 mph, real-world variables, and all the other assumptions in your HRM software.

Of course, even if the average power estimate of 225 watts is close, that doesn't really tell how hard a ride it was. You could have been going deep into the red for those 47 minutes over your "threshold" (however that's estimated), which would make for a lot tougher ride than one done at steady output.

It wasn't trying to blast 50 miles.
On a scale of one to ten, as regards exertion, I was at 80% (this is not flat out and it wasn't taking it easy either).
Good hard workout.

My heart rate aerobic threshold was measured a few years back and was 161
bpm.
So I held my heart rate below that threshold for the 110 minutes of the ride.
For the rest of the time, I was over 161 bpm limit.
At one point, when climbing my bpm rate hit 183.
That's about all of the data that I have from that ride.

(BTW, I used to cycle competitively but that was nearly 18 years ago).

limerickman said:

It wasn't trying to blast 50 miles.
On a scale of one to ten, as regards exertion, I was at 80% (this is not flat out and it wasn't taking it easy either).
Good hard workout.

My heart rate aerobic threshold was measured a few years back and was 161
bpm.
So I held my heart rate below that threshold for the 110 minutes of the ride.
For the rest of the time, I was over 161 bpm limit.
At one point, when climbing my bpm rate hit 183.
That's about all of the data that I have from that ride.

(BTW, I used to cycle competitively but that was nearly 18 years ago).

That 183 you hit is right about my max, and 161 sounds about like the "threshold" HR here as well. On long climbs, I try to keep the HR down to 170; it just feels like the level I can handle for 10-20 minutes without breathing too hard or blowing up. With my triple bike now, it's easier to stay seated and moderate the effort on the steeps.

I also did a couple of seasons of local crits back in the early 90's with my son and another kid. The second season, with guys elbowing me on both sides at 29 mph in the pack, I heard the inner voice saying "you're too old for this stuff". Still remember that experience with clarity.