Benjamin C. Sporer

Inhaled salbutamol and doping control: effects of dose on urine concentrations.

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). Participants:Eight healthy, nonasthmatic males participated in this study (age = 28 ± 6 years, height = 179.4 ± 5.1 cm, and weight = 77.4 ± 5.4 kg). Intervention:Administration of three different doses of inhaled salbutamol (800, 400, and 200 μg) in a randomized fashion separated by at least 72 hours. Main Outcome Measurement:Urine concentration of nonsulphated salbutamol Results:Urine concentrations were highly variable between subjects and increased as dose increased, with a significant difference noted between 800 and 200 μg at 30, 60, and 120 minutes after inhalation. Urine concentrations of salbutamol peaked at 60 minutes for all doses. No samples exceeded the doping criterion of 1000 ng/mL, and the maximum value observed was 904 ng/mL. Conclusion:These results indicate that after inhalation of doses up to 800 μg, urinary concentrations of salbutamol are well below the limits used in doping control.

Acute Beetroot Juice Supplementation Does Not Improve Cycling Performance in Normoxia or Moderate Hypoxia

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. Two hours before exercise, subjects consumed 70 mL BR (~6 mmol nitrate) or placebo (nitrate-depleted BR) in a randomized, double-blind manner. Subjects then completed a 15-min self-selected cycling warm-up, a 15-min steady-state exercise bout at 50% maximum power output, and a 10-km time trial (TT) in either normoxia or hypoxia. Environmental conditions were randomized and single-blind. BR supplementation increased plasma nitrate concentration and fraction of exhaled nitric oxide relative to PL (p < .05 for both comparisons). Economy at 50% power output was similar in hypoxic and normoxic conditions (p > .05), but mean power output was greater in the normoxic TT relative to the hypoxic TT (p < .05). BR did not affect economy, steady-state SpO2, mean power output, or 10-km TT completion time relative to placebo in either normoxia or hypoxia (p > .05 in all comparisons). In conclusion, BR did not lower the oxygen cost of steady-state exercise or improve exercise performance in normoxia or hypoxia in a small sample of well-trained male cyclists.

Inhaled salbutamol does not affect athletic performance in asthmatic and non-asthmatic cyclists

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. Lung function, assessed by forced expiratory volume in 1 s, was measured immediately before and 30 min after inhalation. Performance was measured by mean power output. Measurements & main results Despite a significant increase in lung function after the inhalation of salbutamol compared to the placebo (p<0.001), salbutamol did not affect athletes’ perceptions of dyspnoea (p>0.05) or leg exertion (p>0.05) during exercise. Salbutamol did not affect mean power output: EVH+ and EVH− athletes averaged 4.0 (0.5) and 4.1 (0.5) W/kg after salbutamol and 4.0 (0.5) W/kg and 4.0 (0.4) W/kg after placebo, respectively (p>0.05 for each comparison). Conclusions The inhalation of salbutamol induced a significant increase in resting lung function in EVH+ and EVH− athletes but this improvement in lung function did not translate to improved exercise performance. Salbutamol had no discernible effect on key ventilatory and exercise parameters regardless of EVH challenge outcome.

Canadian Academy of Sport and Exercise Medicine position statement: athletes at high altitude.

Abstract:Many sports incorporate training at altitude as a key component of their athlete training plan. Furthermore, many sports are required to compete at high altitude venues. Exercise at high altitude provides unique challenges to the athlete and to the sport medicine clinician working with these athletes. These challenges include altitude illness, alterations in training intensity and performance, nutritional and hydration difficulties, and challenges related to the austerity of the environment. Furthermore, many of the strategies that are typically utilized by visitors to altitude may have implications from an anti-doping point of view.This position statement was commissioned and approved by the Canadian Academy of Sport and Exercise Medicine. The purpose of this statement was to provide an evidence-based, best practices summary to assist clinicians with the preparation and management of athletes and individuals travelling to altitude for both competition and training.

Effects of inhaled bronchodilators on lung function and cycling performance in female athletes with and without exercise-induced bronchoconstriction

OBJECTIVES 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. METHODS Twenty-one female athletes (6 with exercise-induced bronchoconstriction and 15 without exercise-induced bronchoconstriction) performed a simulated 10-km time-trial on a cycle ergometer 60 min after the inhalation of either 400 μg of salbutamol or placebo. Forced expiratory volume in 1s, was measured immediately before and 30 min after inhalation. Performance was measured by mean power output over the duration of the time trial. RESULTS After salbutamol inhalation, Forced expiratory volume in 1s improved significantly in athletes with exercise-induced bronchoconstriction (M (SD) = 6.1% (47.6)) and athletes without exercise-induced bronchoconstriction (4.0% (3.1); p ≤ 0.02). Mean power output was significantly decreased after salbutamol use (204 W (21)) compared to placebo (208 W (17); p = 0.047), regardless of airway hyperresponsiveness. Relative to placebo, salbutamol significantly increased mean oxygen consumption (46.9 mL kg(-1)min(-1) (5.9) vs. 44.8 mL kg(-1)min(-1) (4.0); p = 0.049) and significantly decreased cycling economy (72.8 W L(-1)min(-1) (6.8) vs. 76.4 W L(-1)min(-1) (4.3); p = 0.01). CONCLUSIONS The inhalation of salbutamol induced a significant increase in lung function in female athletes, but this increased lung function did not translate to improved exercise performance.

Heliox breathing equally influences respiratory mechanics and cycling performance in trained males and females

In 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). Subjects were instrumented with an esophageal balloon for the assessment of respiratory mechanics. During the time trial, we assessed the ability of HeO2 to alleviate mechanical ventilatory constraints in three ways: 1) expiratory flow limitation, 2) utilization of ventilatory capacity, and 3) the work of breathing. We found that HeO2 significantly reduced the work of breathing, increased the size of the maximal flow-volume envelope, and reduced the fractional utilization of the maximal ventilatory capacity equally between men and women. The primary finding of this study was that inspiring HeO2 was associated with a statistically significant performance improvement of 0.7% (3.2 s) for males and 1.5% (8.1 s) for females (P < 0.05); however, there were no sex differences with respect to improvement in time trial performance (P > 0.05). Our results suggest that the extent of sex-based differences in airway anatomy, work of breathing, and expiratory flow limitation is not great enough to differentially affect whole body exercise performance.

One session of interval work does not alter VO2max, peak power or plasma volume

Abstract We examined the effect of one high-intensity cycling workout on aerobic capacity (VO2max), peak cycling power, and estimated change in plasma volume on subsequent days. Eight healthy males (age=29.5±5.3 years, height=1.81±0.09 m, mass=81.5±7.5 kg) visited the laboratory on three occasions. The first visit (D1) included baseline measures of cycling VO2max, haematocrit, and haemoglobin. Following a brief rest, the participants performed a high-intensity cycling workout of six 30-s cycling intervals (modelled on the Wingate cycle test) with each repetition separated by 3 min rest. The final two visits (D2 and D3) included identical measures as the first visit and occurred 48 and 96 h after the interval workout. No significant differences were found for VO2max (53.4±5.3, 53.7±6.7, and 53.7±6.2 ml · kg−1 · min−1), peak power (386±35, 384±35, and 389±35 W) or estimated change in plasma volume [−0.8±8.5% (D1–D2), 1.5±11.5% (D2–D3), and −1.6±9.6% (D1–D3)] between any of the three test days. Our results show that one short-term high-intensity cycling workout does not alter VO2max, peak power or estimated change in plasma volume on subsequent days, and is therefore unlikely to benefit or hinder performance.