30-40 mins of stationary bike every day

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Replies

  • sijomial
    sijomial Posts: 19,735 Member
    @sijomial The table at the site linked earlier is for a stationary bike, not road bike. You're correct that on the road, gravity and air resistance would be huge factors for energy use, but indoors the basic truth still applies that moving more mass to work the pedals requires more energy.

    Here's an article from Harvard Medical School, showing an 84 calories difference in 30 mins of stationary bike in people up to 60 pounds apart. That 84 calories is not from the BMR difference. The BMR difference between a 125 and 185 pound person sitting idle for 30 minutes would be about 10 calories.

    Isn't the net calories the difference between BMR at rest for 30 minutes vs gross calories for the 30 mins of exercise? In this Harvard study then, about 10 of the 84 calories difference would be from BMR, the rest would be from the exercise itself.

    https://www.health.harvard.edu/diet-and-weight-loss/calories-burned-in-30-minutes-for-people-of-three-different-weights

    @Retroguy2000

    But the heavier person isn't moving all that mass! They are weight bearing through their backside.
    The only part moving is their legs, is there a teeny, tiny difference between spinning heavier legs (and circular motions are very efficient) and spinning lighter legs? Yes, but that's focussing on the 1% and not the 99%.

    Could you make a case that in a particular demographic (same gender, age, fitness level...) that heavier people may tend to have higher fitness capabilities (e.g. their "moderate effort" might be producing more power than their lighter same demographic)? Sure, to a very variable degree.
    Extend that across populations including fat and unfit people and that correlation is stretched well beyond breaking point.

    There exist very good ways to get calorie counts cycling (indoors and out) but there also exist extremely generalised methods which have massive ranges of inaccuracy.

    Beware Harvard publish all sorts of stuff on their site - that doesn't make it their study or have merit. More content = more clicks = more revenue.
    Three sources have been cobbled together into one article and I'm not going to drill down to find which bit is the cycling bit or their methodology.

    Just like the METS tables used by MyFitnessPal are a very generalised average from a sample and often hidiously inaccurate on a personal level.

    Sorry you have been misled by a pretty useless article (or more accurately useless in parts).

  • Retroguy2000
    Retroguy2000 Posts: 181 Member
    Wow, every 125 pounds person does the same intensity for 30 minutes - and that makes sense to you?
    Show me where I said that.

    I said heavier people burn more calories on the bike, and I backed that up with reputable sources.

    Others said that's not the case, and provided no sources.

    All you do is keep moving goalposts.
  • Retroguy2000
    Retroguy2000 Posts: 181 Member
    sijomial wrote: »
    Beware Harvard publish all sorts of stuff on their site - that doesn't make it their study or have merit. More content = more clicks = more revenue.
    Three sources have been cobbled together into one article and I'm not going to drill down to find which bit is the cycling bit or their methodology.

    Sorry you have been misled by a pretty useless article (or more accurately useless in parts).
    I see. So the data at both articles I posted is wrong, because you say it is, including the parts you mention above which you haven't double checked, but you know it's wrong anyway, and your source is... yourself saying so. Forgive me, I need a bit more than that.
  • AnnPT77
    AnnPT77 Posts: 25,214 Member
    @sijomial Surely it takes more calories for a heavier person to cycle at the same speed as a lighter person? It takes more energy to move more mass at the same speed.

    (snip)

    If you're seated cycling, on a stationary bike, you're not moving any materially greater mass. (The leg mass being moved may differ, but it's NBD at any reasonably significant intensity, as a percentage of the total effort. The total body mass isn't moving.)

    It's important to understand what kind of estimator you're using (hidden behind a seductively persuasive black-box online "calculator" or fitness tracker). Many of the web sites use METS, which are a way of estimating calorie burn based on body mass. Generically, it's a reasonable approach for many exercises, research-based, all that good stuff.

    In actual real life, it can be better for some exercises than others, analogous to the way that heart rate can be a better way to estimate some exercises vs. others.

    Power meters are a good way to estimate cycling. Other methods are more approximate. How approximate? It depends.
  • sijomial
    sijomial Posts: 19,735 Member
    sijomial wrote: »
    Beware Harvard publish all sorts of stuff on their site - that doesn't make it their study or have merit. More content = more clicks = more revenue.
    Three sources have been cobbled together into one article and I'm not going to drill down to find which bit is the cycling bit or their methodology.

    Sorry you have been misled by a pretty useless article (or more accurately useless in parts).
    I see. So the data at both articles I posted is wrong, because you say it is, including the parts you mention above which you haven't double checked, but you know it's wrong anyway, and your source is... yourself saying so. Forgive me, I need a bit more than that.

    Both articles are wrong because it's dumb to base the ability to produce power on a person's weight during a non-weight bearing activity.
    You have no answers to the multiple examples I've given which disprove whatever unstated theory is behind those websites. Want another personal example from this 40,000 mile cyclist?
    Since winter I've dropped 8lbs and due to fitness improvements seen a tested over 5% increase in sustained power output and resulting calorie burns. That is very normal for a huge range of cyclists from recreational to professional transitioning from the off season back to peak fitness and best weight.

    Cycling is unusual in that there is widely available technology to actually measure the person's power output and hopefully you can realise the link between power and energy.
    The resulting data is freely available - this took me seconds to find on https://www.cyclinganalytics.com/blog/2018/06/how-does-your-cycling-power-output-compare

    87rte65bt7i1.png

    Think of the x5 spread of calorie burns from people at the same weight from a lowly 1w per kg through to an exceptional 5w per kg. That's not exactly useful for estimating based on bodyweight is it?

  • BrianSharpe
    BrianSharpe Posts: 9,160 Member
    @sijomial The table at the site linked earlier is for a stationary bike, not road bike. You're correct that on the road, gravity and air resistance would be huge factors for energy use, but indoors the basic truth still applies that moving more mass to work the pedals requires more energy.

    Cycling indoors you're not moving anything, you're making the wheel go around. To really get a handle on the calories expended you need to know the wattage, anything else is guesswork.