The app or the bike for calories?

Compromisee
Compromisee Posts: 3 Member
edited December 2024 in Fitness and Exercise
Hi guys,

Im new to exercise and healthy eating and have recently bought a exercise bike. It's nothing flash - cost just over £100 but it's got a monitor that tells me how many calories I've burnt.

I was cycling for about 45 mins trying to maintain between 20-22 mph on the middle resistance setting. I didn't feel like my lungs were going to fall out but I was covered in sweat by the time I finished.

I would say that was a moderate workout, didn't feel vigorous in terms of a full blown sprint but my question is when I put 45 mins in the app as a moderate speed it says 517 cals lost whereas the bike says 390.

Which should I go off? Is the app putting more cals in because I'm a larger weight?

Replies

  • AnnPT77
    AnnPT77 Posts: 36,118 Member
    Faced with two estimates, and no particular way to know which is more accurate, I'd be inclined to log the lower estimate.

    If you cycle sitting-only on a stationery bike, your body weight doesn't make a material difference, in practice. (The app is using your weight. If the bike monitor has weight settings, it might be, too.) If the bike has a watts measurement, that might imply that it's doing something semi-reasonable to estimate calories.

    Unfortunately, how you feel is no guide at all to how many calories were burned, at least not until you have some experience and standard of comparison (with a more accurate basis for estimating calories) for a similar activity.

    For example, it might be reasonable for me to use perceived exertion and the well-measured calorie estimates from my rowing machine to reasonableness-test my heart rate monitor's calorie estimate for rowing my rowing shell. I wouldn't be so inclined to use rowing machine experience to reality-test swimming calorie estimates, for example. ;)
  • sijomial
    sijomial Posts: 19,809 Member
    That "speed" bears no relation to real speed outdoors on a bike - ignore it apart from maybe comparing your own rides. You cannot use calorie estimates for outdoor riding speed and translate them to a stationary bike imaginary speed.
    And yes the problem with the MyFitnessPal estimate is partially the app adjusting your calorie burn for your weight when stationary cycling isn't a weight bearing exercise and your weight isn't significant for that exercise.

    Sweating is an irrelevance for calories - it just means you got hot.

    The chances of someone new to exercise putting out more than 10/cals a minute in a moderate workout are remote.
    Go with your bike's estimate for consistency, it's probably not that accurate (probably a bit generous but hard to tell with limited info) but should at least be consistent with the effort you put in.


  • NorthCascades
    NorthCascades Posts: 10,968 Member
    It's very easy to measure bike calories with great precision, it's just expensive.

    The reason the speed it's reading is n to very accurate is because when you're actually moving, you need to work harder to overcome air resistance. If you've ever stuck your hand out the window at freeway speed, you know sorry resistance can bed hard to overcome as you go faster. There isn't really a set formal for this because, for example, your posture has a profound effect on your aerodynamic profile - hope much resistance you face, and how much energy it takes to overcome.

    I agree the bike's number is probably inflated a bit, but obviously much closer to the truth.
  • Compromisee
    Compromisee Posts: 3 Member
    Cheers for the responses guys! I did think that the app was a bit much.. I know I don't really know what is/isn't a good workout but it felt a bit too easy to lose 500 cals in 45 mins!

    Will use the bike from now on but know that it can be a touch misleading
  • BurningChrome44
    BurningChrome44 Posts: 6 Member
    It is for this reason that I set up MFP to lose 0 lbs a week and with a Sedentary life. That way, MFP does what it is good at (tracking calories eaten) and don't worry about what it isn't good at (calories burned).

    I know if I don't work out and eat to maintenance, at least I won't gain anything. Any weight loss comes from exercise, which is good, imo.

    I use the trackers on the machines as benchmarks for setting personal bests, so I know if I am improving and pushing myself. But other than that, I don't worry about it. Going about it this way as seriously reduced my stress and anxiety over calorie counting.
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