Premium
Sex differences in time to task failure and blood flow for an intermittent isometric fatiguing contraction
Author(s) -
Hunter Sandra K.,
Griffith Erin E.,
Schlachter Kristine M.,
Kufahl Tim D.
Publication year - 2009
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.21203
Subject(s) - isometric exercise , medicine , cardiology , contraction (grammar) , forearm , blood flow , plethysmograph , reactive hyperemia , occlusion , muscle contraction , physical medicine and rehabilitation , physical therapy , anatomy
The purpose of this study was to compare the time to task failure, postcontraction hyperemia, and vascular conductance of young men and women for a submaximal intermittent fatiguing contraction performed with the handgrip muscles. Twenty men and 20 women (mean ± SD: 22 ± 4 years) performed an isometric contraction at 50% of maximal voluntary contraction (MVC) (6‐s contraction, 4‐s rest) until task failure. Forearm venous occlusion plethysmography was used to estimate the peak blood flow (after 10‐min occlusion) and blood flow at rest after 6‐s submaximal contractions of varying intensities, and during an intermittent fatiguing contraction at 1‐min intervals and task failure. The time to task failure was longer for the women compared with the men (408 ± 205 s vs. 297 ± 57 s, P < 0.05). Postcontraction hyperemia and vascular conductance were greater for men than for women after nonfatiguing 6‐s submaximal contractions performed at 20%, 40%, 50%, 60%, and 80% of MVC force ( P < 0.05). In contrast, hyperemia and vascular conductance were similar for both genders when measured at 50 s into the fatiguing contraction, at each minute thereafter, and at task failure. Regression analysis indicated that the rate of electromyographic activity and perceived exertion were the significant predictors of the time to task failure. The longer time to task failure for women compared with men for an intermittent fatiguing contraction with handgrip muscles was not explained by postcontraction hyperemia or vascular conductance with fatigue. © 2008 Wiley Periodicals, Inc. Muscle Nerve 39: 42–53, 2009