Metabolic and Neuromuscular Adaptations to Endurance Training in Professional Cyclists : A Longitudinal Study

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Author(s)

Abstract

The aim of this longitudinal study was to analyze the changes in several metabolic and neuromuscular variables in response to endurance training during three defined periods of a full sports season (rest, precompetition and competition). The study population was formed by thirteen professional cyclists (age ± SEM: 24 ± 1 years; mean V(dot)o<sub>2 max </sub>~74 ml·kg<sup>−1</sup>·min<sup>−1</sup>). In each testing session, subjects performed a ramp test until exhaustion on a cycle ergometer (workload increases of 25 W·min<sup>−1</sup>). The following variables were recorded every 100 W until the tests: oxygen consumption (V˙<SUB>O2</SUB> in l·min<sup>−1</sup>), respiratory exchange ratio (RER in V(dot)co<sub>2</sub>·V˙<SUB>O2</SUB><sup>−1</sup>) and blood lactate, pH and bicarbonate concentration [HCO<sub>3</sub><sup>−</sup>]. Surface electromyography (EMG) recordings were also obtained from the vastus lateralis to determine the variables: root mean square voltage (rms-EMG) and mean power frequency (MPF). RER and lactate values both showed a decrease (p < 0.05) throughout the season at exercise intensities corresponding to submaximal workloads. In contrast, no significant differences were found in mean pH or [HCO<sub>3</sub><sup>−</sup>]. Finally, rms-EMG tended to increase during the season, with significant differences (p < 0.05) observed mainly between the competition and rest periods at most workloads. In contrast, precompetition MPF values increased (p < 0.05) with respect to resting values at most submaximal workloads but fell (p < 0.05) during the competition period. Our findings suggest that endurance conditioning induces the following general adaptations in elite athletes: (1) lower circulating lactate and increased reliance on aerobic metabolism at a given submaximal intensity, and possibly (2) an enhanced recruitment of motor units in active muscles, as suggested by rms-EMG data.<br>

Journal

  • The Japanese Journal of Physiology

    The Japanese Journal of Physiology 50(3), 381-388, 2000-06

    THE PHYSIOLOGICAL SOCIETY OF JAPAN

References:  32

Cited by:  1

Codes

  • NII Article ID (NAID)
    10008291667
  • NII NACSIS-CAT ID (NCID)
    AA00691224
  • Text Lang
    ENG
  • Article Type
    Journal Article
  • ISSN
    0021521X
  • NDL Article ID
    5525809
  • NDL Source Classification
    ZS8(科学技術--医学--解剖学・生理学・生化学)
  • NDL Call No.
    Z53-D40
  • Data Source
    CJP  CJPref  NDL  J-STAGE 
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