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DOI: 10.1055/s-2007-972586
© Georg Thieme Verlag Stuttgart · New York
The Pressor Response to Submaximal Cycle Ergometry While Using Aerodynamic Handlebars
Publication History
Publication Date:
09 March 2007 (online)
This study hypothesized that changes in static shoulder loading while using aerobars during submaximal cycle ergometry would elicit a combined static and dynamic pressor response. Seven trained cyclists (x + SD: 22 ± 3 years, 77 ± 12 kg, 1.8 ± 1.1 m) rode a modified Monark cycle ergometer at three inclines (+ 5°, 0°, - 5° for five minutes each using aerobars at a power output (144 ±21 W) eliciting 60-65 % of each subject's age-predicted HR maximum (120 ± 4.9 bts min-1). The positive to negative incline changes were designed to increase the static load experienced by the shoulder musculature. Mean HR, VE, V02, and rectified EMC for the triceps brachii (TB), anterior (AD) and posterior deltoid muscles were computed over each minute <of each condition. All variables exhibited steady-state responses at + 5° and 0° inclines and nonsteady-state responses at - 5°. HIR, V02, and VE correlated highly with EMC from AD (xr = 0.75-0.79) and TB (xr = 0.68-0.75) at - 5°, but only moderately correlated for HR at + 5° and 0° (xr = 0.21 - 0.86). Y-intercepts for HR-VO2 and VE - V02 relationships shifted positively with increased static load. Thus, static loading of AD and TB may disassociate the HR - V02 relationship during submaximal cycle ergomettry and may be responsible for torso positioning preferences by time-trial cyclists.
Key words
Electromyography - time-trial cycling - torso angle