"perhaps the pros, who are racing a tactical race and trying to get into position on the Hawi express need to use those high RPM cadences to generate the early race power requirements that put them in position"
i want to clarify my position. i'm not arguing for a lower cadence on the back end of a 5hr ride coupled with a decreasing drop in power, even as a result of tactical choices made by pro athletes. i'm guessing, or postulating, that one might self-select, for good reason, a lower cadence while more or less maintaining his power throughout the ride. i did ask about this of darren smith, whom i referred to earlier in this thread. he quickly jotted off the following to me in reply (some is hard to follow because he really quickly answered this:
"The long and the short of it: we know that self selected cadence changes over time (duration of the ride) and also at diff wattages (ie as % of max sustainable) for everyone as different stages of preparation, skill and strength. Economy or efficiency is a whole new ball game, you can measure Vo2 and the low point for that (called energetically optimal) is lower than self selected cadence, more so when athletes are fresh, with the two points becoming closer the longer the duration. If you happen to measure neuromuscular components of muscle at the same time by EMG you find that the 'the neural most optimal' cadences are significantly higher. A Japanese group also saw that venous blood return was also enhanced with a higher pedal rate, and for me that started to form a picture for me why everyone talked about higher cadences for cycling, while scientifically the VO2 data had always indicated otherwise. Christophe Hausswirth et al in the late 90s have done the best work on that topic using all of the above techniques (search http://www.pubmed.com) and I was also part of that research group on a few of those studies. They were the first studies to look at what happens to self selected cadence after more than one hour of cycling at a decent wattage. The same group has just published something along similar lines but with more emphasis on correlating strength characteristics with energetically optimal and self selected cadences, albeit the durations are not consistent with this discussion in LC racing (International journal of sports med, 2007).
The best papers on Neural fatigue during cycling however come from Dr Romauld Lepers of Dijon, France who incidentally competed in the male elite field at Hawaii last year, so he clearly knows his stuff from a practical and scientific point of view (eg. Neuromuscular Fatigue during a long-duration cycling exercise; Lepers et al. Jnl Applied Physiol, 92: 1487-1493, 2002). As mentioned above, central neural fatigue seems to kick in after a number of hours and this restricts the cadence possible.... However, from a practical point of view it will only negatively affect the resultant power output you can push (not withstanding the other issues of heat, fuel, efficiency of pedalling etc) if you theoretically do not have the specific (strength endurance) conditioning to absorb the greater torque resulting from a lower cadence."
so that's what darren said, and i think it speaks to my query, which is by no means yet a theory let alone anything approaching a truism. it's my own observation that deserves my own consideration -- that is, it's something i'm exploring.
Dan Empfield
aka Slowman
i want to clarify my position. i'm not arguing for a lower cadence on the back end of a 5hr ride coupled with a decreasing drop in power, even as a result of tactical choices made by pro athletes. i'm guessing, or postulating, that one might self-select, for good reason, a lower cadence while more or less maintaining his power throughout the ride. i did ask about this of darren smith, whom i referred to earlier in this thread. he quickly jotted off the following to me in reply (some is hard to follow because he really quickly answered this:
"The long and the short of it: we know that self selected cadence changes over time (duration of the ride) and also at diff wattages (ie as % of max sustainable) for everyone as different stages of preparation, skill and strength. Economy or efficiency is a whole new ball game, you can measure Vo2 and the low point for that (called energetically optimal) is lower than self selected cadence, more so when athletes are fresh, with the two points becoming closer the longer the duration. If you happen to measure neuromuscular components of muscle at the same time by EMG you find that the 'the neural most optimal' cadences are significantly higher. A Japanese group also saw that venous blood return was also enhanced with a higher pedal rate, and for me that started to form a picture for me why everyone talked about higher cadences for cycling, while scientifically the VO2 data had always indicated otherwise. Christophe Hausswirth et al in the late 90s have done the best work on that topic using all of the above techniques (search http://www.pubmed.com) and I was also part of that research group on a few of those studies. They were the first studies to look at what happens to self selected cadence after more than one hour of cycling at a decent wattage. The same group has just published something along similar lines but with more emphasis on correlating strength characteristics with energetically optimal and self selected cadences, albeit the durations are not consistent with this discussion in LC racing (International journal of sports med, 2007).
The best papers on Neural fatigue during cycling however come from Dr Romauld Lepers of Dijon, France who incidentally competed in the male elite field at Hawaii last year, so he clearly knows his stuff from a practical and scientific point of view (eg. Neuromuscular Fatigue during a long-duration cycling exercise; Lepers et al. Jnl Applied Physiol, 92: 1487-1493, 2002). As mentioned above, central neural fatigue seems to kick in after a number of hours and this restricts the cadence possible.... However, from a practical point of view it will only negatively affect the resultant power output you can push (not withstanding the other issues of heat, fuel, efficiency of pedalling etc) if you theoretically do not have the specific (strength endurance) conditioning to absorb the greater torque resulting from a lower cadence."
so that's what darren said, and i think it speaks to my query, which is by no means yet a theory let alone anything approaching a truism. it's my own observation that deserves my own consideration -- that is, it's something i'm exploring.
Dan Empfield
aka Slowman
85–95 rpm to