In professional road cyclists, low pedaling cadences are less efficient.
OBJECTIVE
To determine the effects of changes in pedaling frequency on the gross efficiency (GE) and other physiological variables (oxygen uptake (VO2), HR, lactate, pH, ventilation, motor unit recruitment estimated by EMG) of professional cyclists while generating high power outputs (PO).


METHODS
Following a counterbalanced, cross-over design, eight professional cyclists (age (mean +/- SD): 26 +/- 2 yr, VO2max: 74.0 +/- 5.7 mL x kg x min) performed three 6-min bouts at a fixed PO (mean of 366 +/- 37 W) and at a cadence of 60, 80, and 100 rpm.


RESULTS
Values of GE averaged 22.4 +/- 1.7, 23.6 +/- 1.8 and 24.2 +/- 2.0% at 60, 80, and 100 rpm, respectively. Mean GE at 100 rpm was significantly higher than at 60 rpm (P < 0.05). Similarly, mean values of VO2, HR, rates of perceived exertion (RPE), lactate and normalized root-mean square EMG (rms-EMG) in both vastus lateralis and gluteus maximum muscles decreased at increasing cadences.


CONCLUSIONS
In professional road cyclists riding at high PO, GE/economy improves at increasing pedaling cadences.
Lucia
Alejandro
A
Exercise Physiology Laboratory, European University of Madrid, Madrid, Spain. alejandro.lucia@mrfs.cisa.uem.es
San Juan
Alejandro F
AF
Montilla
Manuel
M
CaNete
Silvia
S
Santalla
Alfredo
A
Earnest
Conrad
C
Pérez
Margarita
M
D000328:Adult; D001642:Bicycling / Q000502:physiology; D004576:Electromyography; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007773:Lactates / Q000032:analysis; D010101:Oxygen Consumption
D007773:Lactates