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

M.P. Bell, R.A. Ferguson

Research output: Contribution to journalArticle

21 Citations (Scopus)

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 O2 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.
LanguageEnglish
Pages763-769
Number of pages6
JournalJournal of Applied Physiology
Volume107
Issue number3
DOIs
Publication statusPublished - Sep 2009

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Muscle Contraction
Exercise
Muscles
Temperature
Foot
Skeletal Muscle
Lung

Keywords

  • energy turnover
  • efficiency/velocity relationship
  • elderly
  • pedal frequency

Cite this

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title = "Interaction between muscle temperature and contraction velocity affects mechanical efficiency during moderate-intensity cycling exercise in young and older women",
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 O2 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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T1 - Interaction between muscle temperature and contraction velocity affects mechanical efficiency during moderate-intensity cycling exercise in young and older women

AU - Bell, M.P.

AU - Ferguson, R.A.

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N2 - 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 O2 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.

AB - 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 O2 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.

KW - energy turnover

KW - efficiency/velocity relationship

KW - elderly

KW - pedal frequency

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