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Scientific tips

Read an article today that stated something like this:

Elevation of rpm= elevation of heart rate, but with same power output.

So it could be for example that 70 rpm is better than 100rpm .

On the other hand I think it's a very personal thing.

Comments

  • TommiTriTommiTri Posts: 879
    Hello all,



    As you know, I'm injured and so very very bored! So I have done my usual thing of looking at some performance related research. Just thought I would share a few findings with you.



    1. triathletes vs cyclists in muscle adaptation.



    I just read an article that compared us triathletes with cyclists of the same level (doing exactly the same cycling training) and showed that the muscular adaptation in triathletes is slower than straight cyclists, resulting in less performance gains. The reason? Brick sessions, by following cycling by running within 4hours following the bike session there was less neuromuscular adaptation. But when these triathletes were changed to doing running approximately 6-8 hours after the bike session they matched the cyclists for performance development.



    So the message was, use brick training as simply a method of preparing your body for the transition, if you want to get the best out of cycling training separate it from running in most sessions. Interesting huh?



    2. Cycling cadence of running performance.

    a much overdone topic I know, but I have never found a really good bit of evidence yet, until now!



    I know the cadence choice has been done to death, I personally feel happier at a cadence of 80-90 rather than the 90-100 choice of some I know. But ok heres what the study found. It found that running performance over 3km following 20k on the bike at 60, 80, 100 rpm that performance was actually better marginally at 60rpm! I know it seems to go against what were told, but they found that although the 60rpm group were slower over the 1st 500m they returned to normal (ish) running speed after 500 and kept this speed throughout the race, but the 100 rpm group were faster over the 500m, but gradually got slower in the last 1k.



    This was the result of an increased metabolic cost by cycling at 100rpm.



    Sorry its been a bit dry, just thought I would share my findings with you all. :)
  • bennybenny Posts: 1,314
    found the link, hope it works this time:

    http://users.telenet.be/wim.de.doncker1/november/Etips.html

    It's the article called : Air resistance/cadans/power.

    Lots of other interesting stuff here as well.
  • Jack HughesJack Hughes Posts: 1,262
    Very interesting. I'm all for a bit of science.



    I seem to remember, going back to my youth, that the really elite cycling time trialists pushed very big gears at a relatively low cadence - these were doing <50 mins. for 25 miles..

  • jon_gjon_g Posts: 318
    i thought the whole point of higher cadence was to take the stress off your musles and put it on the cardiovascular system (as benny pointed out)? so it's up to the individual to decide what they want to be strained. as i tend to go for longer races i prefer higher cadence cos i've trained that way so i know my heart and lungs can handle it. if i was doing a sprint race i would be pushing a harder gear a t a lower cadence cos i'd know my muscles dont have to last that long
  • JulesJules Posts: 987
    I'm just experimenting with this cadence idea. I've never thought about it before and have just pounded away in the hardest gear a can. I found I was doing about 60 rpm.



    I've now had a go at pedalling a easier gear, but at about 90rpm.



    To me at least the latter option seems to allow me to maintain my speed over a longer distance. If I've run afterwards this seems less tiring too. I guess this means I have weedy leg muscles not up to the challenge of the hard gear low cadence option.
  • TommiTriTommiTri Posts: 879
    The reason I posted this was because I had a conversation last year with a Dr in sports science about cadence and he wondered whether having a higher cadence in the bike might be good for the initial part of the run, but then prove to be a metabolic cost so that the fatigue was higher towards the end of the run.

    Ive been searching for evidence to back this up/disprove it for a while, and i think this serves well to back it up!
  • I also did a PhD in Ex Phys and i would agree with the other one mentioned on the cadence issue! (in addition my Msc thesis was on cycling so i had to do a lot of specific reading...). It is generally accepted in the scientific community that a slower (~60rpm) cadence is more efficient than the faster one (~80-100rpm) that many cyclists use and therefore the research result that you've just seen makes complete sense. It's true that for most people the faster cadence seems easier and this appears to trick us into believing that it is easier. There are certainly reasons for accepting this inefficiency in some types of races, (for example the ability to quickly accelerate or follow a break in a group race) however for most of us involved in non-drafting races the lower cadence will probably lead to a faster overall time.



    On the brick sessions idea; that's interesting and again makes sense from a scientific perspective and it also pleases me (in a rather self-satisfied smug way!) as i never saw a reason for doing brick sessions apart from the psychological 'get used to the wobbly legs feeling' and simply practicing the mechanics of getting shoes on and off etc. My physiological view was always do separate sessions and focus on each one and then do a few 'bricks' just to practice transitions.

  • graham33graham33 Posts: 265
    TommiTri,



    that is very intresting indeed!



    It's funny because I always feel better on the run when I cycle at slower cadances - I'll stick with how I feel in future!



    thanks
  • BritspinBritspin Posts: 1,655
    But isn't most (all?) cadence research done on cyclists..who get off after Xhours at X cadence, fall onto the team bus, wee in a pot, get harassed by the press etc, rather than racking the bike & bogging off for a run?
  • TommiTriTommiTri Posts: 879
    this cadence research was done on elite triathletes only!
  • This somewhat contradicts a study reported in another thread. Someone has pointed out that the most efficient cadence for running is 180 steps per minute. After first reading that, I assumed it gave credence to the recommendation that we should maintain a cycling cadence of 90rpm as that would mean that we would keep the same leg speed throughout the bike ride and run and supposedly reduce the difficulty of transition.



    My own feeling on cycling cadence is that we each have a preference for a certain cadence. If I use the analogy of a car: different car engines develop their maximum power at a certain rate of revolution hence in order to get the most out of the engine you change gear so that you can vary your ground speed but still stay as close as possible to this ideal. Lance Armstrong famously has a high cadence and this works excellently for him, Jan Ullrich had a much lower cadence and it worked excellently for him. I would suggest that you should find a cadence that doesn't put undue strain on your legs for a given speed and alter your gearing for inclines in order to maintain this cadence.

  • TommiTriTommiTri Posts: 879
    Ah yes, you've hit on my point exactly.



    Part of my point I was making with this evidence was to support the own preference when it comes to cadence, as you pointed out Mr Git two of cyclists top performers had very different cadence choices. This I believe was largely related to size, with ullrich being quite large and so found larger gears more efficient for him and lance being quite lean and going for high cadence.



    So yeh my point was that we don't all have to aim for a high cadence because we believe it will make us faster. All in all the results did not differ hugely, with only a very slight lean towards the lower cadence, however the run was only very short so this may increase with a longer run.



    In regards to running its a bit of a different kettle of fish, with the 180 cadence being largely related to the use of elastic energy which requires a high cadence to utilize it properly. So yeh the idea about the 90rpm is right, as in this evidence the 100rpm group were faster over the first 500m, but lost it in the last part.
  • Jack HughesJack Hughes Posts: 1,262
    Cadence on the bike and cadence running do not really have anything to do with each other. Running, it's all about minimising the amount of contact, and as TommiTri says utilitising the elastic energy.



    On the bike its all continuous and smooth delivery of power.



    One thing that has not been mentioned is the difference in terrain/environmental conditions. The bike is probably not too different from the car - you only get into 5 or 6th gear on the motorways - if you drop the speed to just about the lowest it can do before stalling, don't accelerate or decelerate, then you get the most efficient use of fuel.



    Endurance cycling is largely about efficiency - you want the biggest most powerful engine operating at it's most efficient (rather than sprints etc.)



    In the same way that you when you get off the motorway - hills, stops/starts etc. you start to use different gears. The same is true of the bike.



    If you are on undulating terrain, then a lower gear and higher revs - even though you are using a bit more energy, might be better on the whole. As the impact of a hill when pushing a higher gear and low revs would probably be to use much more energy to react to the changing conditions than a lower gear would.



    I don't know if the research originally mentioned covers any of this (headwind being another key factor).



    Moral: There's no one right way - it will all depend on conditions and your pariticular strength/weaknesses - and you have to adapt to the conditions. Which makes it all the more interesting!

  • All down to body type but makes for an interesting read.



    I have been told i pedal to fast and wear myself out...so i adjust, then someone says pedalling too slow will wear me out???



    May natural cadence is 100rpm. But for brut power i drop down to 80ish....but beware the lactic!
  • bennybenny Posts: 1,314
    I naturally do about 80-85 rpm, until I was told that was no good:YOU SHOULD GO for 100, they said.

    Only a month or 2 later I realised they were wrong: go for you natural rpm that feels best(like running style).

    The research shows slight advantadge for lower rpm's when long runs follow, but try to change too radically and you won't feel good with it I suppose.
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