Benjamin C. Sporer

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.

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). On days 2-5, athletes performed a 20-km time trial 15 min after inhalation (PI) of placebo, 200 microg (D2), 400 microg (D4), or 800 microg (D8) of SAL. At 60 min PI, urine samples were provided. All conditions were randomized and double blinded, with repeated-measures ANOVA used to determine effects of dose. Post hoc analysis was done with Tukey's HSD test. RESULTS: Seven subjects had positive responses to the EVH test, resulting in a 19% incidence within this sample; they were excluded from further participation in this study. The remaining subjects (N = 30) had a V O 2max of 67.1 (4.3) mL x kg(-1) x min(-1) and Pmax of 457 (31) W (W). There was no effect of dose on completion time (P > 0.05), mean power (P > 0.05), or mean heart rate (P > 0.05). Similarly, SAL had no effect on any metabolic or ventilatory parameters (P > 0.05). Urine cSAL increased with dose and was highly variable, with the peak value observed being 831 ng x mL(-1) after a dose of 800 microg. Moderate but significant correlations were noted between cSAL and urine specific gravity at higher doses (D4, r = 0.42; D8, r = 0.37). CONCLUSIONS: These findings suggest that inhaled SAL does not enhance time-trial performance, regardless of dose, and that urine cSAL after exercise is related to dose, demonstrates high variability, and is partially related to hydration status.

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.

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.

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 microg) 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 microg 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 microg, urinary concentrations of salbutamol are well below the limits used in doping control.