How many calories am I really burning?

[ColinJ]

but if you have en electronic computer on your excercise bike that adjusts the drag settings automatically which then ups the calorie expenditure accordingly its much easier

It would be way more useful than the stupid calories-burned guesstimate that my device makes but I would be surprised if most affordable domestic equipment is accurately calibrated and gives consistent results.

 

[VamP]

It would be way more useful than the stupid calories-burned guesstimate that my device makes but I would be surprised if most affordable domestic equipment is accurately calibrated and gives consistent results.

or indeed expensive gym equipment. It is a well known fact that fitness industry massages the egos of it's customers with exercise bikes, treadmills, calculators etc that generally wildly overestimate energy consumption.

I think the rule of thumb you gave above is pretty much on the money, and would recommend it to the OP or indeed anyone else who wants to estimate calorific consumption for the purpose of weight control.

 

[jowwy]

or indeed expensive gym equipment. It is a well known fact that fitness industry massages the egos of it's customers with exercise bikes, treadmills, calculators etc that generally wildly overestimate energy consumption.

I think the rule of thumb you gave above is pretty much on the money, and would recommend it to the OP or indeed anyone else who wants to estimate calorific consumption for the purpose of weight control.

when i was 19stone i was using 50 calories per mile - since dropping down to 15stone i now use 40 calories per mile and it seems to be working out ok for me

 

[VamP]

when i was 19stone i was using 50 calories per mile - since dropping down to 15stone i now use 40 calories per mile and it seems to be working out ok for me

I think you're wildly overestimating, but making up for it elsewhere. So long as you're happy that's all that matters.

 

[MrJamie]

Well firstly all they provide is a rough guide anyway.

From riding with a power meter, my experience is that stop/start riding and hilly rides actually lead to significantly lower average power than a flat (ish) road with no or minimal stops. The reason being that you just can't make up for the zero-effort parts (coasting and waiting at junctions) with the 'on' periods. My average power through the city is very low compared to what I do when I get a clear bit of road with no stops. Similarly, properly hilly rides with long descents lead to lower power than flat (ish) rides where I can keep a relatively constant (and actually quite modest compared to what I'd climb a hill at) power output.

Lower average power means lower calorie burn so I'd disagree with your statement for general riding (not so sure about you extreme example, but that's not real world riding).

Interesting Id guess those rides with more "on time" had higher average speeds and hence calorie counts though?

I know for example that if i ride on a road route my average speed is higher and so calorie estimate is higher. Say I try to average 15mph through certain parts of the cycle paths here, where im slowed very very frequently to brake for a junction, brake for people/dogs or take a narrow 90 degree corner it knackers my average speed, but on open road where i can average a bit more, I feel like i can sustain 15mph with much less effort because im not accelerating my mass up constantly. I agree as you say road cycling should burn more calories than urban (unless youre riding like that brunelle guy), but stop start urban cycling should be further off the estimate.

Good point! Yes, they all assume constant speed. At least the one I linked to takes the weight of the bike (remember to include the weight of your clothes, drinks, tools and spares too) and wind speed into account.

My cheapo gym bike has a calories burned function which works by measuring how many revs the flywheel does during the session. All very well, except that it does not have any way of knowing how much friction I have set on the drag brake! I can wind the brake off the wheel or do it up so tight that I can't turn the pedals without standing on them and it is all the same to the computer. I ignore it apart from the timer which I use to time my intervals.

I got an exercise bike a few years ago when i woke up to my very poor fitness, its not bad i think its a magnetic brake on a 30kg flywheel and HRM, you adjust the resistance through the computer though so it knows what youre doing. I dont often use it anymore but ive been tempted to put a spoon saddle on it as it has a clamp for normal rails and use it in winter. The calorie estimates and mph on it increase dramatically depending on the level of resistance you set and interestingly enough last time i used it, I got nearly the exact same mph average as I do on a real bike, same crazy alleged calorie burn too. I think when I first got it I would do about 400 cals per hour and now it says about 1200, so while it might be nonsense numbers it shows how bad my fitness was

 

[amaferanga]

Interesting Id guess those rides with more "on time" had higher average speeds and hence calorie counts though?

I know for example that if i ride on a road route my average speed is higher and so calorie estimate is higher. Say I try to average 15mph through certain parts of the cycle paths here, where im slowed very very frequently to brake for a junction, brake for people/dogs or take a narrow 90 degree corner it knackers my average speed, but on open road where i can average a bit more, I feel like i can sustain 15mph with much less effort because im not accelerating my mass up constantly. I agree as you say road cycling should burn more calories than urban (unless youre riding like that brunelle guy), but stop start urban cycling should be further off the estimate.

I think you may be confusing perceived effort with calories burnt though. For example I could go out and do 5x1min intervals with a couple of minutes rest between intervals. Total time riding of only 13min, but if I did the intervals as hard as I could it'd be a fecking hard 13 minutes and would leave me quite fatigued. But since I'm resting and soft pedalling between the big efforts, the average power would actually be fairly low. I could very easily ride steadily for 13min at a higher average power - it'd probably feel really easy actually - and the calorie burn would be greater.

 

[MrJamie]

I think you may be confusing perceived effort with calories burnt though. For example I could go out and do 5x1min intervals with a couple of minutes rest between intervals. Total time riding of only 13min, but if I did the intervals as hard as I could it'd be a fecking hard 13 minutes and would leave me quite fatigued. But since I'm resting and soft pedalling between the big efforts, the average power would actually be fairly low. I could very easily ride steadily for 13min at a higher average power - it'd probably feel really easy actually - and the calorie burn would be greater.

I agree with that about the intervals, but im talking more about the inaccuracy of these programs estimating calorie consumption purely by distance/speed, in relation to recovering momentum lost by braking not being accounted for (rather than just riding at different intensities). What im trying to get at is that if you look at a common local cycle facility here http://goo.gl/maps/OFCY or here http://goo.gl/maps/Jemk, in the simplest sense i can either a) ride unhindered down the road at a constant 15mph or b) ride at say 15mph along the cyclepath, which requires me to slow down for every single side road because theyre almost always obscured and then not only build the speed back but go faster to keep my average up and keep up with my "ghost rider". At the end of the hours riding with 15 miles covered at 15mph in both scenarios, surely the guy who has used the cycle facility has put in considerably more power and hence because so much of it has been wasted under braking. According to the phone app or garmin gps tracker both cyclists will have covered the same distance in the same time and therefore burnt the same calories, despite one being a 15mph cruise and the other really struggling to keep that average speed up.