Article

Neuromuscular, metabolic, and kinetic adaptations for skilled pedaling performance in cyclists.

Institute of Natural Sciences, Nagoya City University, Nagoya, Japan.
Medicine &amp Science in Sports &amp Exercise (Impact Factor: 4.46). 03/1998; 30(3):442-9. DOI: 10.1097/00005768-199803000-00016
Source: PubMed

ABSTRACT The purpose of this study was to clarify the reason for the difference in the preferred cadence between cyclists and noncyclists.
Male cyclists and noncyclists were evaluated in terms of pedal force, neuromuscular activity for lower extremities, and oxygen consumption among the cadence manipulation (45, 60, 75, 90, and 105 rpm) during pedaling at 150 and 200 W. Noncyclists having the same levels of aerobic and anaerobic capacity as cyclists were chosen from athletes of different sports to avoid any confounding effect from similar kinetic properties of cyclists for lower extremities (i.e., high speed contraction and high repetitions in prolonged exercise) on both pedaling performance and preferred cadence.
The peak pedal force significantly decreased with increasing of cadence in both groups, and the value for noncyclists was significantly higher than that for cyclists at each cadence despite the same power output. The normalized iEMG for vastus lateralis and vastus medialis muscles increased in noncyclists with rising cadence; however, cyclists did not show such a significant increase of the normalized iEMG for the muscles. On the other hand, the normalized iEMG for biceps femoris muscle showed a significant increase in cyclists while there was no increase for noncyclists. Oxygen consumption for cyclists was significantly lower than that for noncyclists at 105 rpm for 150 W work and at 75, 90, and 105 rpm for 200 W work.
We conclude that cyclists have a certain pedaling skill regarding the positive utilization for knee flexors up to the higher cadences, which would contribute to a decrease in peak pedal force and which would alleviate muscle activity for the knee extensors. We speculated that pedaling skills that decrease muscle stress influence the preferred cadence selection, contributing to recruitment of ST muscle fibers with fatigue resistance and high mechanical efficiency despite increased oxygen consumption caused by increased repetitions of leg movements.

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    ABSTRACT: The aim of this work was to verify the hypothesis that the lowering of the pedalling rate (elicited by the increase of the exterior load) during maximal efforts performed with identical work amount causes the growth of the generated power (until the maximal values are reached) and next its fall and does not influence the gross and net mechanical efficiency changes. The above experiment was conducted with 13 untrained students who performed 5 maximal efforts with the same work amount. The first was the 30 s maximal effort (Wingate test) with the load equal 7.5% of the body weight (BW). The amount of work performed in this test was accepted as the model value for following tests to achieve. Every 3 days, each examined had next trials consisting of maximal efforts on the cycle ergometer with loads of: 2.5, 5, 10, 12.5% BW and lasting until the value of power reached in the 30 s Wingate test occurred. Changing of the external load elicited various pedalling velocity. The force-velocity (F-v) and power-velocity (P-v) dependence was calculated for every examined subject basing on the results of performed maximal efforts. The maximal power (P max) and optimal velocity (v o) were calculated basing on the P-v relationship depicted with the second order polynomial equation. The gas analyser (SensorMedics) equipped with the 2900/2900c Metabolic Measurements Cart/System software was used as for the oxygen output measuring during maximal efforts performance and in the resting phase. The ventilation and gas variable changes were monitored breath-by-breath in the open ventilation system. The POLAR-SportTester was used for the heart retraction (HR) measurement during both: efforts and resting. The capillary blood was taken from the fingertip before the test and: immediately after it, every 2 min for the first 10 min of the rest and in the 20 th min of resting. The blood was used for the acid-base balance determination with the use of the blood gas analyser – Ciba-Corning 248. The average pedalling rate decreased during effort from 151.5 rpm to 80 rpm and the power grew from 293.5 W to 761 W along with the increase of the load from 2.5% to 12.5% BW. Powers varied among specific trials with the
    Biology of Sport 01/2005; 22(1):35-51. · 0.53 Impact Factor
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    K Buśko, Krzysztof Buśko
    [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this work was to verify the hypothesis that the lowering of the pedalling rate (elicited by the increase of the exterior load) during maximal efforts performed with identical work amount causes the growth of the generated power (until the maximal values are reached) and next its fall and does not influence the gross and net mechanical efficiency changes. The above experiment was conducted with 13 untrained students who performed 5 maximal efforts with the same work amount. The first was the 30 s maximal effort (Wingate test) with the load equal 7.5% of the body weight (BW). The amount of work performed in this test was accepted as the model value for following tests to achieve. Every 3 days, each examined had next trials consisting of maximal efforts on the cycle ergometer with loads of: 2.5, 5, 10, 12.5% BW and lasting until the value of power reached in the 30 s Wingate test occurred. Changing of the external load elicited various pedalling velocity. The force-velocity (F-v) and power-velocity (P-v) dependence was calculated for every examined subject basing on the results of performed maximal efforts. The maximal power (P max) and optimal velocity (v o) were calculated basing on the P-v relationship depicted with the second order polynomial equation. The gas analyser (SensorMedics) equipped with the 2900/2900c Metabolic Measurements Cart/System software was used as for the oxygen output measuring during maximal efforts performance and in the resting phase. The ventilation and gas variable changes were monitored breath-by-breath in the open ventilation system. The POLAR-SportTester was used for the heart retraction (HR) measurement during both: efforts and resting. The capillary blood was taken from the fingertip before the test and: immediately after it, every 2 min for the first 10 min of the rest and in the 20 th min of resting. The blood was used for the acid-base balance determination with the use of the blood gas analyser – Ciba-Corning 248. The average pedalling rate decreased during effort from 151.5 rpm to 80 rpm and the power grew from 293.5 W to 761 W along with the increase of the load from 2.5% to 12.5% BW. Powers varied among specific trials with the
    Biology of Sport 01/2005; 22(1):35-51. · 0.53 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this work was to verify the hypothesis that the lowering of the pedalling rate (elicited by the increase of the exterior load) during maximal efforts performed with identical work amount causes the growth of the generated power (until the maximal values are reached) and next its fall and does not influence the gross and net mechanical efficiency changes. The above experiment was conducted with 13 untrained students who performed 5 maximal efforts with the same work amount. The first was the 30 s maximal effort (Wingate test) with the load equal 7.5% of the body weight (BW). The amount of work performed in this test was accepted as the model value for following tests to achieve. Every 3 days, each examined had next trials consisting of maximal efforts on the cycle ergometer with loads of: 2.5, 5, 10, 12.5% BW and lasting until the value of power reached in the 30 s Wingate test occurred. Changing of the external load elicited various pedalling velocity. The force-velocity (F-v) and power-velocity (P-v) dependence was calculated for every examined subject basing on the results of performed maximal efforts. The maximal power (P max) and optimal velocity (v o) were calculated basing on the P-v relationship depicted with the second order polynomial equation. The gas analyser (SensorMedics) equipped with the 2900/2900c Metabolic Measurements Cart/System software was used as for the oxygen output measuring during maximal efforts performance and in the resting phase. The ventilation and gas variable changes were monitored breath-by-breath in the open ventilation system. The POLAR-SportTester was used for the heart retraction (HR) measurement during both: efforts and resting. The capillary blood was taken from the fingertip before the test and: immediately after it, every 2 min for the first 10 min of the rest and in the 20 th min of resting. The blood was used for the acid-base balance determination with the use of the blood gas analyser – Ciba-Corning 248. The average pedalling rate decreased during effort from 151.5 rpm to 80 rpm and the power grew from 293.5 W to 761 W along with the increase of the load from 2.5% to 12.5% BW. Powers varied among specific trials with the
    Biology of Sport 01/2005; 22(1):35-51. · 0.53 Impact Factor