The pressor response to submaximal cycle ergometry while using aerodynamic handlebars.
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 (mean +/- SD: 22 +/- 3 years, 77 +/- 12 kg, 1.8 +/- 1.1 m) rode a modified Monark cycle ergometer at three inclines (+5 degrees, 0 degree, -5 degrees) 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, VO2, and rectified EMG 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 degrees and 0 degree inclines and nonsteady-state responses at -5 degrees.HR, VO2, and VE correlated highly with EMG from AD (mean r = 0.75-0.79) and TB (mean r = 0.68-0.75) at -5', but only moderately correlated for HR at +5 degrees and 0 degree (mean r = 0.21-0.86). Y-intercepts for HR-VO2 and VE-VO2 relationships shifted positively with increased static load. Thus, static loading of AD and TB may disassociate the HR-VO2 relationship during submaximal cycle ergometry and may be responsible for torso positioning preferences by time-trial cyclists.
Heil
D P
DP
Department of Exercise Science, University of Massachusetts, Amherst, MA, USA.
D000328:Adult; D001642:Bicycling; D001794:Blood Pressure / Q000502:physiology*; D004576:Electromyography; D016552:Ergometry; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D010101:Oxygen Consumption / Q000502:physiology*; D012119:Respiration / Q000502:physiology*; D012782:Shoulder / Q000502:physiology*