Body weight and climbing ability

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Comments

  • Tom Dean wrote:
    But you didn't even know the other guy's weight! You guessed. I'm not sure what you think you have learned.

    Obviously there are many other factors contributing to speed, e.g. aerodynamics. However at low speeds on steep hills these tend to be so small as to be negligible which is why
    Speed up steeper climbs is directly proportional to your power to weight ratio.
    holds for practical purposes.

    What is your point? Note that I guessed his weight correctly as previously stated within a few kgs. Just luck you think?

    You forgot to quote the 'holds for practical purposes' originally. I was expanding on this and provided a real life example. I am not sure why you are struggling with this... but lets not continue this pointless discussion.
    Simon
  • bahzob
    bahzob Posts: 2,195
    Something known as "shifting baseline syndrome" applies to this discussion. It was first coined to explain the extinction, through overfishing, of the Newfoundland cod stocks. Slow moving changes are difficult to perceive so each generation re-establishes a baseline and uses that. Over time the result is a gradual shift in the baseline, so that what was once exceptional becomes the norm.

    Peoples perceptions of what is "overweight", "fat", "thin" have been subject to a baseline shift. It is easy to demonstrate this. The much maligned BMI meaasure originated as a simple description of height/weight ratios of a population, only that population was over a hundred years ago. Since then food has become cheaper and we have got used to eating more, exercising less so "fat" has become the new "thin". Those aware of BMI apply various defence reactions like "big bones" to explain why it doesn't apply to them. The irony is that while it is true that it can be inexact in estimating body fat it does so in the wrong direction (so a direct measure of body fat% shows a higher proportion of people are obese than BMI does).

    Bradley Wiggins is the perfect example to illustrate this wrt this topic.

    He is 1.9m tall and, famously, reduced his weight to 69kg, a key factor in making him a competitive climber. He is frequently described as being incredibly thin, he has gone from Wiggo to Twiggo.

    Do the sums. http://www.nhlbisupport.com/bmi/bmi-m.htm

    His BMI is 19.1. Towards the bottom of the "normal" range. He is not dangerously thin, a much greater proportion of the population used to be this type and function quite OK which is why he can get down to this weight with no noticeable loss of power and climb much quicker as a result.

    Bottom line: Plug your height and weight into the link above. Unless you showing a result that indicates you are underweight, if want to climb more easily the single best thing to do is lose fat.
    Martin S. Newbury RC
  • Tom Dean
    Tom Dean Posts: 1,723
    springtide9, I can't tell if you are trying to prove the principle, or show its limitations. (You haven't done either.)
  • napoleond
    napoleond Posts: 5,992
    I've lost a fair bit of weight recently and with very little on the bike training I recently did a PB up a short test hill (1.1 mile artists lane in Alderley edge) beating my prev best by over 2 mins.
    Insta: ATEnduranceCoaching
    ABCC Cycling Coach
  • springtide9
    springtide9 Posts: 1,731
    edited September 2012
    Tom Dean wrote:
    springtide9, I can't tell if you are trying to prove the principle, or show its limitations. (You haven't done either.)

    I was providing a practical example of the increase in power required to climb a hill, of 8.9% gradient, comparing two people of different weights. Nothing more, nothing less.

    I was also stating that power to weight ratio although useful for general riding ability in mixed terrain, doesn't tell the full story when the gradient increases. The steeper the hill, the less power to weight ratio is relevant, as weight is the bigger factor in determining speed (or performance)

    I personally believe the above isn't that hard to understand. You either don't understand the above, or you are trying to making the above statements into something they are not.

    Note that if you punch in the values that I have stated in my previous posts (body weight, hill gradient, speed) and calculate the values using http://bikecalculator.com - you will notice that the practical test holds pretty close to the theoretical value calculated by bikecalculator.com.
    Simon
  • napoleond
    napoleond Posts: 5,992
    I have to disagree. The greater the gradient the more power to weight ratio is relevant. IME.
    Insta: ATEnduranceCoaching
    ABCC Cycling Coach
  • NapoleonD wrote:
    I have to disagree. The greater the gradient the more power to weight ratio is relevant. IME.

    Just as a FYI

    - Create two riders, one 80kg and one 60kg
    - Calculate their power/weight ratio (watts/kg) so that they are identical (i.e. the heavier rider has more power)
    - Use the calculator http://bikecalculator.com to calculate their speed up a 5% gradient, 10%, 15%, 20% & 25% (or more)

    If their power to weight ratios are identical, their speeds should also be identical. What you will find is that as the gradient increases, weight is the bigger factor (as you have to overpower gravity)
    You could also increase the power/weight ratio of the heavier rider so that it's 10% higher than the lighter rider and see what results you get.
    Simon
  • napoleond
    napoleond Posts: 5,992
    I'm speaking from my experience, not a theoretical model.
    Insta: ATEnduranceCoaching
    ABCC Cycling Coach
  • smidsy
    smidsy Posts: 5,273
    Blimey - using the BMI calculator I am just in the normal range (verging on overweight).

    What surprises me is according to the calculator, based on my height I can lose 18kg and still be in the normal range (albeit now verging on underweight).

    Thats a lot of scope. In fact I am almost carrying a bag of cement everywhere!!!! :shock:
    Yellow is the new Black.
  • Tom Dean
    Tom Dean Posts: 1,723
    Tom Dean wrote:
    springtide9, I can't tell if you are trying to prove the principle, or show its limitations. (You haven't done either.)

    I was providing a practical example of the increase in power required to climb a hill, of 8.9% gradient, comparing two people of different weights. Nothing more, nothing less.
    You knew someone's time and had a rough idea of his power. How can you draw any useful conclusion from these?
    I was also stating that power to weight ratio although useful for general riding ability in mixed terrain, doesn't tell the full story when the gradient increases. The steeper the hill, the less power to weight ratio is relevant, as weight is the bigger factor in determining speed (or performance)

    I personally believe the above isn't that hard to understand. You either don't understand the above, or you are trying to making the above statements into something they are not.
    You didn't make that statement before now, so I could hardly have been responding to it, whether I understood or not.

    edit: in fact you seem to have stated the exact opposite:
    There are other hills that I can compare, but the steeper the hill the more power to weight matters rather than overall power.
  • Losing the weight will make you massively faster, as will getting fitter. However, if you are finding it is easier to walk than to cycle, perhaps you need to fit some lower gears. All this talk about climbing power-to-weight etc only holds under the assumption that you have a range of gears which allows you to achieve your peak power output across the range of speeds you ride at.

    If you are struggling to turn your lowest gear, then the chances are you could generate more power in a lower gear pedalling faster (or generate the same power in a way less fatiguing to your muscles). Consider a compact or triple if you don't already use one.
  • davidof
    davidof Posts: 3,118
    ben16v wrote:
    i hate hill climb season! i drop from top 3rd-5th in sporting club TT`s to double figures on the hill climbs! 5`10" 83kg just dont go up hill very fast even though the bike is lighter and the HR is the same!
    although the hills are pretty tough
    http://app.strava.com/rides/22883571#408696948

    Interesting. I just did a side by side with you (I'm the same height and weight) and we had very similar VAMS and power outputs.

    According to that BMI calculator thingy we could both loose 25kgs and still be "normal" weight. Jeez I'd be quicker than Bradley Wiggins if I lost that much.
    BASI Nordic Ski Instructor
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  • smidsy
    smidsy Posts: 5,273
    davidof wrote:
    ben16v wrote:
    i hate hill climb season! i drop from top 3rd-5th in sporting club TT`s to double figures on the hill climbs! 5`10" 83kg just dont go up hill very fast even though the bike is lighter and the HR is the same!
    although the hills are pretty tough
    http://app.strava.com/rides/22883571#408696948

    Interesting. I just did a side by side with you (I'm the same height and weight) and we had very similar VAMS and power outputs.

    According to that BMI calculator thingy we could both loose 25kgs and still be "normal" weight. Jeez I'd be quicker than Bradley Wiggins if I lost that much.

    This is what got me thinking - the BMI thing has to be taken with a pinch of salt - no way can someone lose over 3 1/2 stone and still be in the same range...surely. :?
    Yellow is the new Black.