Strava & Calories. How accurate?

bluedoggy
bluedoggy Posts: 284
edited December 2012 in Road general
Curious to know how accurate Strava is concerning the calories burned after a ride? Did I REALLY burn 600 calories after that 15 mile ride?
Wilier cento uno.

Comments

  • danowat
    danowat Posts: 2,877
    Usually, without a power meter, not very.

    If you base your cal consumption on about 600-700 an hour at top end of endurance level, that's not far off
  • So it probably was 300 calories - not 600. I'm not at the top end endurance level but here in the Bath Area you get a good work out with all the undulating hills. Interesting. And I was thinking I was burning what it said. Ultimately it doesn't really matter because I've got much, much fitter and lighter.
    Wilier cento uno.
  • Herbsman
    Herbsman Posts: 2,029
    I think there is a 50% margin of error.

    How can it know whether you're riding at 14mph because you're doing a recovery ride, or because you're pushing hard into a headwind?

    How can it know you're not sheltering behind six other cyclists when you're doing 24mph?
    CAPTAIN BUCKFAST'S CYCLING TIPS - GUARANTEED TO WORK! 1 OUT OF 10 RACING CYCLISTS AGREE!
  • Apart from the Hugely expensive power meters, what device can give a better reading?
    Wilier cento uno.
  • danowat
    danowat Posts: 2,877
    Nothing, without knowing how much work you are doing, you can only guess, even a HRM doesn't know how much work you are doing, just how fast your heart is beating.
  • So what is the consensus about reading a Strava calorie workout and eating? Do you simply read it as 50% and go with that as a best bet?
    Wilier cento uno.
  • Bobbinogs
    Bobbinogs Posts: 4,841
    Bluedoggy wrote:
    So what is the consensus about reading a Strava calorie workout and eating? Do you simply read it as 50% and go with that as a best bet?

    I eat the quantity of food I feel is right and don't rely on a webpage to advise me how much :)
  • danowat
    danowat Posts: 2,877
    It's about 25% over for me vs my power meter
  • Bobbinogs wrote:
    Bluedoggy wrote:
    So what is the consensus about reading a Strava calorie workout and eating? Do you simply read it as 50% and go with that as a best bet?

    I eat the quantity of food I feel is right and don't rely on a webpage to advise me how much :)

    I would totally agree and probably the best way. But i have to say those webpages you comment on have given me a 'Helping hand' along the way and made a huge difference to my well being. And now i don't use them as gospel. :wink:
    Wilier cento uno.
  • Bluedoggy wrote:
    So what is the consensus about reading a Strava calorie workout and eating? Do you simply read it as 50% and go with that as a best bet?
    My theory...

    Calorie balance on the day is (more or less )... intake - BMR - exercise - other = net.

    The problem with that is intake's very hard to measure accurately unless you have a remarkably controlled diet, unless there's a lab handy you're not going to know what the body's doing with it anyway, BMR's a guess unless there's a lab handy, exercise is (for the most part) another guess, and "other" is a total and utter punt that can vary by as much as the sum of the other parts depending on line of work. Consequently, actually trying to put all the elements together to get a useable number is probably beyond most people.

    However, what isn't beyond most people is weighing themselves regularly, and getting dressed, then assessing the results and taking the appropriate action ("eat less\more and do less\more exercise, delete as appropriate"). In other words, it's probably best to just change behaviour based on observed results because they're the only part of the equation that stands a chance of being accurate.
    Mangeur
  • amaferanga
    amaferanga Posts: 6,789
    danowat wrote:
    It's about 25% over for me vs my power meter

    Unlikely to be similar for everyone though obviously.
    More problems but still living....
  • danowat
    danowat Posts: 2,877
    amaferanga wrote:
    danowat wrote:
    It's about 25% over for me vs my power meter

    Unlikely to be similar for everyone though obviously.

    Obviously, and I wouldn't say a power meter is 100% accurate anyway............
  • Bluedoggy wrote:
    So what is the consensus about reading a Strava calorie workout and eating? Do you simply read it as 50% and go with that as a best bet?
    My theory...

    Calorie balance on the day is (more or less )... intake - BMR - exercise - other = net.

    The problem with that is intake's very hard to measure accurately unless you have a remarkably controlled diet, unless there's a lab handy you're not going to know what the body's doing with it anyway, BMR's a guess unless there's a lab handy, exercise is (for the most part) another guess, and "other" is a total and utter punt that can vary by as much as the sum of the other parts depending on line of work. Consequently, actually trying to put all the elements together to get a useable number is probably beyond most people.

    However, what isn't beyond most people is weighing themselves regularly, and getting dressed, then assessing the results and taking the appropriate action ("eat less\more and do less\more exercise, delete as appropriate"). In other words, it's probably best to just change behaviour based on observed results because they're the only part of the equation that stands a chance of being accurate.

    +1 for that! Common sense in other words??
    Wilier cento uno.
  • Bluedoggy wrote:
    +1 for that! Common sense in other words??
    Yep, pretty much common sense and trusting reality.

    The whole calorie counting thing bugs me because it reminds me very much of the way some (not all) people end up treating systems (I'm a programmer). The statement "if the model\process is correct, and the inputs are accurate, then the model\process represents reality" ends up as "if the model\process is correct, and the inputs are accurate, then the model\process represents reality" in their minds, which leads to either poor assumptions regarding the future, or (more amusingly) the assertion that reality is, in fact, wrong.
    Mangeur
  • Herbsman wrote:
    I think there is a 50% margin of error.

    How can it know whether you're riding at 14mph because you're doing a recovery ride, or because you're pushing hard into a headwind?

    How can it know you're not sheltering behind six other cyclists when you're doing 24mph?

    From your heart rate if you have a monitor on?
  • t.m.h.n.e.t
    t.m.h.n.e.t Posts: 2,265
    Bluedoggy wrote:
    +1 for that! Common sense in other words??
    Yep, pretty much common sense and trusting reality.

    The whole calorie counting thing bugs me because it reminds me very much of the way some (not all) people end up treating systems (I'm a programmer). The statement "if the model\process is correct, and the inputs are accurate, then the model\process represents reality" ends up as "if the model\process is correct, and the inputs are accurate, then the model\process represents reality" in their minds, which leads to either poor assumptions regarding the future, or (more amusingly) the assertion that reality is, in fact, wrong.

    You make a choice as to which method you trust.

    "Eat less - move more" a pretty baseless statement that offers zero insight.(which as far as I'm concerned,the people who offer this advice should be repeatedly slapped with their own hands)

    Or BMR X activity - deficit. A number which can be changed - a number which will change relative to you.

    I use the latter, to an extent of 5st loss over a certain period. Happily maintaining the weight I am now, losing more isn't a rush job.

    And I have never counted a single calorie in that time(in the context that the phrase is paraded around)
    James H-S wrote:
    Herbsman wrote:
    I think there is a 50% margin of error.

    How can it know whether you're riding at 14mph because you're doing a recovery ride, or because you're pushing hard into a headwind?

    How can it know you're not sheltering behind six other cyclists when you're doing 24mph?

    From your heart rate if you have a monitor on?
    Your heart rate measured in Beats Per Minute, cannot tell you these things. It can tell you how fast your heart is beating.

    Heart rate for example cannot tell the difference between 2hrs cycling and 2hrs lifting heavy things in a gym. Both activities will have grossly different calorie expenditure.
  • So in a nutshell then, just forget about counting calories, ride well and eat sensibly. :D

    So if Strava and others are so hugely inaccurate why are they built in then? Who does it benefit and what does it tell you :|
    Wilier cento uno.
  • I used the myfitnesspal app to monitor calorie intake and exercise for a month. I already had a pretty healthy diet but using the app gave me a better understanding of what I was eating and allowed me change my diet slightly to see positive results e.g. salad rather than sandwich at lunch, porridge for breakfast not sugary cereals etc

    I'm naturally very slim so wanted to maintain the same weight rather than lose a significant amount, plus I wanted to make sure I was eating the right foods at the right time to allow me to cycle long distances.

    I found it to be a really useful exercise and it's given me a good framework of what foods to eat if I want to stay slim and healthy. And now I don't need to use the app anymore, I just trust my own judgement.
  • I used the myfitnesspal app to monitor calorie intake and exercise for a month. I already had a pretty healthy diet but using the app gave me a better understanding of what I was eating and allowed me change my diet slightly to see positive results e.g. salad rather than sandwich at lunch, porridge for breakfast not sugary cereals etc

    I'm naturally very slim so wanted to maintain the same weight rather than lose a significant amount, plus I wanted to make sure I was eating the right foods at the right time to allow me to cycle long distances.

    I found it to be a really useful exercise and it's given me a good framework of what foods to eat if I want to stay slim and healthy. And now I don't need to use the app anymore, I just trust my own judgement.

    +1
    That app and cycling and the weight dropped off. I did use Strava calories with this so even though Strava is not honest with calories, it worked for me. So the original question of mine sort of worked for me?
    Wilier cento uno.
  • Herbsman
    Herbsman Posts: 2,029
    Bluedoggy wrote:
    So in a nutshell then, just forget about counting calories, ride well and eat sensibly. :D

    So if Strava and others are so hugely inaccurate why are they built in then? Who does it benefit and what does it tell you :|
    Haha it's not there to benefit people :lol:

    It's there for the same reason that other non-useful / non-accurate things (for example Zodiac columns in newspapers) exist... it's a feature that adds interest... people like to see how many calories they've used, even if it's completely wrong....
    CAPTAIN BUCKFAST'S CYCLING TIPS - GUARANTEED TO WORK! 1 OUT OF 10 RACING CYCLISTS AGREE!
  • Herbsman
    Herbsman Posts: 2,029
    Bluedoggy wrote:
    I used the myfitnesspal app to monitor calorie intake and exercise for a month. I already had a pretty healthy diet but using the app gave me a better understanding of what I was eating and allowed me change my diet slightly to see positive results e.g. salad rather than sandwich at lunch, porridge for breakfast not sugary cereals etc

    I'm naturally very slim so wanted to maintain the same weight rather than lose a significant amount, plus I wanted to make sure I was eating the right foods at the right time to allow me to cycle long distances.

    I found it to be a really useful exercise and it's given me a good framework of what foods to eat if I want to stay slim and healthy. And now I don't need to use the app anymore, I just trust my own judgement.

    +1
    That app and cycling and the weight dropped off. I did use Strava calories with this so even though Strava is not honest with calories, it worked for me. So the original question of mine sort of worked for me?

    Of course an app or websitethat encourages you to exercise and to eat more healthily is going to help you lose weight no matter how inaccurate the calorie estimates, simply because it encourages and reminds you to take these positive actions regularly.
    CAPTAIN BUCKFAST'S CYCLING TIPS - GUARANTEED TO WORK! 1 OUT OF 10 RACING CYCLISTS AGREE!
  • FlacVest
    FlacVest Posts: 100
    Herbsman wrote:
    It's there for the same reason that other non-useful / non-accurate things (for example Zodiac columns in newspapers) exist... it's a feature that adds interest... people like to see how many calories they've used, even if it's completely wrong....

    Exactly. I wonder what the baseline they're using is made up of; how much wind do they account for on average?

    What I should do, is do 1 normal ride on a bike with a power meter, then use that as a baseline and gauge the percent error of my HR monitor.

    I don't know if my HR monitor's numbers are accurate, but it is consistent; I feel myself bonking around 2000 Calories.