Struggling to 'believe in' calories burned on stationary bike

[LaurieFairyCake]

According to my Fitbit I've just burned off 258 calories cycling for 15 minutes (24 miles an hour, 6 miles).

I also googled and returned the same number on different websites.

Feels like a lot of calories burned ? Do others mistrust it?

I am pretty overweight though so I suppose I have to work quite hard to exercise

I don't have any faith in these watches to be honest, if they were correct I would be tiny!!

I am 5'7" and 13 stone and did a fairly hard core spinning class this morning on my Peloton for 30 minutes. The Peloton says I burnt 274 calories and I went 8.5 miles and my Garmin watch says 220 calories. This particular class has had 60,000 people take it and I came in at around 30,000 so I was mid range I guess in terms of achievement/fitness so not totally out of shape and we did some fairly difficult intervals and hills, I was puffing, bright red and sweating. I would think 258 calories for 15 minutes is a little far fetched.

Sounds reasonable, if you're already pretty overweight and got your heart rate up to peak/cardio for all or most of that 15 minutes.

Bear in mind that if you just pottered around the house doing 15 minutes active housework, you may burn half that amount.

Very roughly, in 15 minutes you burn the same number of calories as your average power output in watts. 258 watts is realistic for a competitive amateur cyclist (Bradley Wiggins could maintain 450W for an hour). So if you're in decent shape, maybe!

Ooh literally 2 saying no and two saying yes

Google, the bike itself and my Fitbit say yes. I was at 113 average heart rate.

Way more overweight than loubilou

Your calorie burn is a straight line, which it won't have been. This indicates it is very definitely a guesstimate and not accurate.

Did you type in that you were travelling at 24mph? Because you can't / won't have been doing exactly 24mph for every second of that while time. This is where the calorie burn estimation error will come from.

If you biked outside, connected to GPS and your HR watch, then you will get a much more accurate calorie burn amount because you'll get realtime data on your speed from moment to moment.

You may also need to do a bit longer than 15m to get an accurate reading.

For comparison, my calorie burn rate in fat burn zone is around 5 cals/min

I did 20 minutes on the gym bike, did 8km and the bike said I’d burned about 120 calories

Looks high. I've just looked at a couple of the workouts I've done on a gym bike via my Apple Watch. 35mins, total calories 268, average heart rate 118, another one 34 mins, 247 cals Ave HR 247.

It's a stationary bike. Interestingly the Fitbit said I was doing 24 mph AND the bike said the same thing in its readings - heart rate, distance, mph all the same on the bikes monitor and the Fitbit

I can't do longer than 15 minutes yet

24mph is FAST!!! I would believe the number if you did that on the road, esp. if you're quite large.

My static bike claims that I burn 39 calories per mile. Energy expended is mass times distance, so in calorie terms it doesn’t matter whether you pedal fast or slow, it’s just the distance covered. Similarly, running a mile burns the same calories as walking a mile - you just get there quicker, and put your heart and breathing rate up higher.

If you are unfit I would expect your heart rate to be through the roof to do 6 miles in 15 minutes! 113 average over 15 mins is really not that high

With that heart rate, You'd have to be male, 20yo 200kg to get that calorie burn, actually, so something doesn't add up.

FEMALE 20yo 200k only burns 122 kcal. Ain't it grand being a girl?

I'm so confused now

What are you trying to achieve? That might help..I exercise for me and try to ignore calories burnt as much as I can, I never eat them back and count them as a bonus to any diet I do. Reason I ignore them? Because I have come to learn that all the watches and machines are incorrect and if I try and eat any exercise calories I either don’t lose weight or I put on. Concentrate on cycling for longer periods and increasing distance for now maybe.

I have half the Estimated calorie burn for all fitness classes. I don't eat the stars I use them to make up for any calorie error calculations and bowl scrapings etc.

Whoops, auto correct made a nonsense of my post!
I half estimated calories earned via a exercise.
tend to ignore the extra calories and use them to make up for forgotten nibbles and underestimated calories!

I find that fitbits aren’t that great of tracking heart rate during excercise so this is for the same class, my polar is a cheat hrm (cal on Fitbit have been edited to match the polar which I trust more)

That's still 531 calories burned off in 45 minutes

So if I'm much more overweight than you (I really will be ) it is possible that the calorie count for my 15 minutes is true ?

LaurieFC: you can calc your calorie burn using this online form.
There are lots of the same form on other webpages, to double check your numbers.

I used to wear a heart rate monitor and polar watch - spin 45 minutes was often 500-600 calories a session so approximately 10 calories a minute. This was with an average hr of 150+ and a maximum of 185

If you're tying to lose weight then mistrusting it is probably no bad thing! Treating calories lost through exercise as a 'bonus' rather than extra calories I was allowed to eat worked much better for me.

What was you watts reading? That will really give a better indication of how hard you were working

ivy - not really though. 100 watts for a regular cyclist wouldn't get there heart rate up too much, but 100 watts for beginner with below average fitness would get their heart rate up pretty high.