Objective: To determine the effects of single nucleotide polymorphisms (SNPs) in the adrenergic β2-receptor gene (ADRB2, rs1042713, and rs1042714) and epithelial Na channel gene (SCNN1A, rs2228576) on cycling performance after the inhalation of salbutamol.
Design: Randomized double-blind, mixed-model repeated measures.
Setting: University Research Setting.
Beetroot juice (BR) has been shown to lower the oxygen cost of exercise in normoxia and may have similar effects in hypoxia. We investigated the effect of BR on steady-state exercise economy and 10-km time trial (TT) performance in normoxia and moderate hypoxia (simulated altitude: ~2500 m). Eleven trained male cyclists (VO 2peak ≥ 60 ml · kg(-1) · min(-1)) completed four exercise trials.
View Article and Find Full Text PDFIn this study we tested the hypothesis that inspiring a low-density gas mixture (helium-oxygen; HeO2) would minimize mechanical ventilatory constraints and preferentially increase exercise performance in females relative to males. Trained male (n = 11, 31 yr) and female (n = 10, 26 yr) cyclists performed an incremental cycle test to exhaustion to determine maximal aerobic capacity (V̇o2max; male = 61, female = 56 ml·kg(-1)·min(-1)). A randomized, single-blinded crossover design was used for two experimental days where subjects completed a 5-km cycling time trial breathing humidified compressed room air or HeO2 (21% O2:balance He).
View Article and Find Full Text PDFObjectives: Inhaled β2-agonists may cause differential effects on lung function and athletic performance in female compared to male athletes. The objective of this study was to compare the effects of inhaled β2-agonists on lung function and cycling performance between female athletes with and without exercise-induced bronchoconstriction and with previously published data on men.
Design: Double-blind crossover randomized controlled trial.
Rationale: Salbutamol may affect lung function and exercise performance differently in individuals with and without asthma.
Objectives: To compare the effects of inhaled salbutamol on lung function, exercise performance and respiratory parameters during cycling exercise in athletes with a positive response to a eucapnic voluntary hyperpnoea (EVH+) and negative (EVH-) challenge, indicative of exercise-induced bronchoconstriction.
Methods: In a randomised controlled trial with a crossover design, a total of 49 well-trained male athletes (14 EVH+ and 35 EVH-) performed two simulated 10 km time-trials on a cycle ergometer 60 min after the inhalation of either 400 μg of salbutamol or a placebo.
Objective: The present study was designed to examine the dose-response relationship of inhaled salbutamol and its concentration in the urine while resting at various times after inhalation, and to compare these values against the current World Anti-Doping Code limits.
Design: An interventional, repeated-measures design.
Setting: Sport Medicine Clinic, University of British Columbia (Vancouver, Canada).
Med Sci Sports Exerc
January 2008
Purpose: This study determined the dose-response effects of inhaled salbutamol (SAL) on time-trial performance and urine concentrations of SAL (cSAL).
Methods: Nonasthmatic, trained male cyclists and triathletes (N = 37) were studied. Day 1 consisted of screening for airway hyperresponsiveness, using a eucapnic voluntary hyperpnea test (EVH), followed by an incremental exercise test to determine V O 2max and peak power (P max).
Noninvasive imaging techniques have been used to assess pulmonary edema following exercise but results remain equivocal. Most studies examining this phenomenon have used male subjects while the female response has received little attention. Some suggest that women, by virtue of their smaller lungs, airways, and diffusion surface areas may be more susceptible to pulmonary limitations during exercise.
View Article and Find Full Text PDFVentilatory responsiveness to hypoxia (HVR) has been reported to be different between highly trained endurance athletes and healthy sedentary controls. However, a linkage between aerobic capacity and HVR has not been a universal finding. The purpose of this study was to examine the relationship between HVR and maximal oxygen consumption (VO2 max) in healthy men with a wide range of aerobic capacities.
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