The Lab is Far from the Road
18 Feb 2004
More than a century has passed since the adoption of crank arms on bicycles, yet the discussion over their optimal use is still open!
Which is the ideal pedaling cadence, what is the optimal crank arm length?
Hundreds of scientific research works and serious studies have been published in prestigious journals and other publications, but, as often occurs, the results have been contradictory and non-decisive.
There may indeed be several reasons for this, but in my opinion the following are the most significant:
- Participants in the majority of the studies were not professional athletes but normal subjects.
- Pedaling in a laboratory, on cyclo-ergometers or other simulators is definitely different from pedaling on the roads or on the track.
- The majority of the studies evaluated and considered only efforts of moderate intensity (200-250 Watts); only very few of them explored 300 Watts levels, while we all know that professional or serious cyclists reach much higher intensities.
- In practically all the studies subjects pedaled exclusively in a seated position, at a constant intensity, while road cyclists alternate seated distances with off saddle periods, often varying the intensity.
- The majority of the authors of such studies were talented scientists and/or laboratory physiologists, with experience and mentality that had very little had to do with the realities of competitive sports.
These are the main reasons why the results of such studies had little practical application.
Only when physiologists get out of their laboratories and dedicate themselves to the study of top-level cyclists, will information be applicable to athletes.
Some researchers (Med. Sci. Sports Exerc., 2001; 33: 1361-1366) did evaluate professional cyclists pedaling cadences while racing, pointing out that athletes use higher cadences than the ones that were considered ideal in laboratory results.
Swaine and Wilcox, in a brilliant and original study done in 1992 (Med. Sci. Sports Exerc., 1992; 24: 1123-1127), had several competitive cyclists pedaling with their own bikes on an uphill treadmill with a 10% gradient, in both seated and off saddle positions, keeping constant cadences of 41 and 84 RPM, ponting out a definite advantage with the higher cadence.
It might therefore be interesting to show the various effects of pedaling cadences on Tony Rominger (Bordeaux, 1994), performing 5 sessions of 5 km each on the track, flying start, and trying to keep the same speed for all of them (between 54.79 e 54.96 km/h) while using different gear ratios (therefore different RPM values).
(T stands for time; V stands for speed in Km/h; rapporto is gear development in m; FC is Heart Rate; [LA] stands for Lactic Acid concentration in mM/l; pediv. stands for crank arm length in cm).
Cadences of 102-103 RPM correspond to lower Lactic Acid concentrations if compared to cadences of 97 and 107 RPM.
Obviously these observations concern only one athlete, but it really is the single individual that has to be evaluated case by case, rather than the statistical significance of the behaviour of a group of athletes.