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Randomized Controlled Trial
. 2009 Sep;107(3):763-9.
doi: 10.1152/japplphysiol.91654.2008. Epub 2009 Jul 9.

Interaction between muscle temperature and contraction velocity affects mechanical efficiency during moderate-intensity cycling exercise in young and older women

Martin P Bell  1 , Richard A Ferguson
Affiliations
Randomized Controlled Trial

Interaction between muscle temperature and contraction velocity affects mechanical efficiency during moderate-intensity cycling exercise in young and older women

Martin P Bell et al. J Appl Physiol (1985). 2009 Sep.

Abstract

The effect of elevated muscle temperature on mechanical efficiency was investigated during exercise at different pedal frequencies in young and older women. Eight young (24 +/- 3 yr) and eight older (70 +/- 4 yr) women performed 6-min periods of cycling at 75% ventilatory threshold at pedal frequencies of 45, 60, 75, and 90 rpm under control and passively elevated local muscle temperature conditions. Mechanical efficiency was calculated from the ratio of energy turnover (pulmonary O(2) uptake) and mechanical power output. Overall, elevating muscle temperature increased (P < 0.05) mechanical efficiency in young (32.0 +/- 3.1 to 34.0 +/- 5.5%) and decreased (P < 0.05) efficiency in older women (30.2 +/- 5.6 to 27.9 +/- 4.1%). The different effect of elevated muscle temperature in young and older women reflects a shift in the efficiency-velocity relationship of skeletal muscle. These effects may be due to differences in recruitment patterns, as well as sarcopenic and fiber-type changes with age.

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Figures

Fig. 1.
Fig. 1.
Muscle temperature measured immediately before moderate-intensity exercise in control (no prior heating) and heated muscle temperature conditions. Muscle temperature data for each participant are the average of each measurement under each temperature condition. Values are means ± SD. *Significant (P < 0.05) difference between young (Y) and older subjects (O). †Significant (P < 0.05) difference from control condition.
Fig. 2.
Fig. 2.
Net O2 uptake (V̇o2) during moderate-intensity exercise at different pedal frequencies in control (no prior heating) and heated muscle temperature conditions. Values are means ± SD. *Significant (P < 0.05) difference from 45 and 60 rpm. †Significant (P < 0.05) difference between Y and O.
Fig. 3.
Fig. 3.
Net efficiency (A) and mechanical efficiency (B) during moderate-intensity exercise at different pedal frequencies in control (no prior heating) and heated muscle temperature conditions in Y and O. Values are means ± SD. *Significant (P < 0.05) difference from 45 rpm. †Significant (P < 0.05) difference from control condition.
Fig. 4.
Fig. 4.
Correlations between proportion of myosin heavy chain I isoform and the change in mechanical efficiency with heating at different pedal frequencies in Y.
See this image and copyright information in PMC

References

    1. Altenberg TM, Degens H, van Mechelen W, Sargeant AJ, De Haan A. Recruitment of single muscle fibers during submaximal cycling exercise. J Appl Physiol 103: 1752–1756, 2007. - PubMed
    1. Andersen JL, Terzis G, Kryger A. Increase in the degree of coexpression of myosin heavy chain isoforms in skeletal muscle fibers of the very old. Muscle Nerve 22: 449–454, 1999. - PubMed
    1. Asmussen E, Bøje O. Body temperature and the capacity for work. Acta Physiol Scand 10: 1–22, 1945.
    1. Beaver KL, Wasserman K, Whipp BJ. A new method for detecting anaerobic threshold by gas exchange. J Appl Physiol 60: 2020–2027, 1986. - PubMed
    1. Beelen A, Sargeant AJ, Lind A, De Haan A, Kernell D, van Mechelen W. Effect of contraction velocity on the pattern of glycogen depletion in human muscle fibre types. In: Neuromuscular Fatigue, edited by Sargeant AJ, Kernell D. Amsterdam: Royal Netherlands Academy of Arts and Sciences, 1993, p. 93–96.

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