Effect of cold exposure (-15 degrees C) and Salbutamol treatment on physical performance in elite nonasthmatic cross-country skiers

SINTEF, Nidaros, Sør-Trøndelag, Norway
European Journal of Applied Physiology and Occupational Physiology 04/1998; 77(4):297-304. DOI: 10.1007/s004210050337
Source: PubMed

ABSTRACT The effects of whole-body exposure to ambient temperatures of -15 degrees C and 23 degrees C on selected performance-related physiological variables were investigated in elite nonasthmatic cross-country skiers. At an ambient temperature of -15 degrees C we also studied the effects of the selective beta2-adrenergic agonist Salbutamol (0.4 mg x 3) which was administered 10 min before the exercise test. Eight male cross-country skiers with known maximal oxygen uptakes (VO2max) of more than 70 ml x kg(-1) x min(-1) participated in the study. Oxygen uptake (VO2), heart rate (fc), blood lactate concentration ([La-]b) and time to exhaustion were measured during controlled submaximal and maximal running on a treadmill in a climatic chamber. Lung function measured as forced expiratory volume in 1 s (FEV1) was recorded immediately before the warm-up period and at the conclusion of the exercise protocol. Submaximal VO2 and [La-]b at the two highest submaximal exercise intensities were significantly higher at -15 degrees C than at 23 degrees C. Time to exhaustion was significantly shorter in the cold environment. However, no differences in VO2max or fc were observed. Our results would suggest that exercise stress is higher at submaximal exercise intensities in a cold environment and support the contention that aerobic capacity is not altered by cold exposure. Furthermore, we found that after Salbutamol inhalation FEV1 was significantly higher than after placebo administration. However, the inhaled beta2-agonist Salbutamol did not influence submaximal and maximal VO2, fc, [La-]b or time to exhaustion in the elite, nonasthmatic cross-country skiers we studied. Thus, these results did not demonstrate any ergogenic effect of the beta2-agonist used.

Download full-text


Available from: Leif Hilding Bjermer, Feb 05, 2014
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Ambient temperature can affect physical performance, and an ambient temperature range of −4 °C to 11 °C is optimal for endurance performance in male athletes. The few similar studies of female athletes appear to have found differences in response to cold between the genders. This study investigated whether ambient temperature affects female endurance performance. Nine athletes performed six tests while running on a treadmill in a climatic chamber at different ambient temperatures: 20, 10, 1, −4, −9 and −14 °C and a wind speed of 5 m∙s−1. The exercise protocol consisted of a 10-minute warm-up, followed by four 5-minute intervals at increasing intensities at 76, 81, 85, and 89% of maximal oxygen consumption. This was followed by an incremental test to exhaustion. Although peak heart rate, body mass loss, and blood lactate concentration after the incremental test to exhaustion increased as the ambient temperature rose, no changes in time to exhaustion, running economy, running speed at lactate threshold or maximal oxygen consumption were found between the different ambient temperature conditions. Endurance performance during one hour of incremental exercise was not affected by ambient temperature in female endurance athletes.
    Journal of Thermal Biology 10/2014; DOI:10.1016/j.jtherbio.2014.06.009 · 1.54 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Inhaled β2-agonists are commonly used as bronchodilators in the treatment of asthma. Their use in athletes, however, is restricted by anti-doping regulations. Controversies remain as to whether healthy elite athletes who use bronchodilators may gain a competitive advantage. The aim of this systematic review and meta-analysis is to assess the effects of inhaled and systemic β2-agonists on physical performance in healthy, nonasthmatic subjects. To this end, MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched up to August 2009. Reference lists were searched for additional relevant studies. The search criteria were for randomized controlled trials examining the effect of inhaled or systemic β2-agonists on physical performance in healthy, nonasthmatic subjects. Two authors independently performed the selection of studies, data extraction and risk of bias assessment. Parallel-group and crossover trials were analysed separately. Mean difference (MD) and 95% confidence intervals were calculated for continuous data and, where possible, data were pooled using a fixed effects model. Twenty-six studies involving 403 participants (age range 7–30 years) compared inhaled β2-agonists with placebo. No significant effect could be detected for inhaled β2-agonists on maximal oxygen consumption (V̇O2max) [MD −0.14mL•kg−1•min−1; 95% CI −1.07, 0.78; 16 studies], endurance time to exhaustion at 105–110% V̇O2max (MD −1.5 s; 95% CI −15.6, 12.6; four studies), 20-km time trial duration (MD −4.4 s; 95% CI −23.5, 14.7; two studies), peak power (MD −0.14 W•kg−1; 95% CI −0.54, 0.27; four studies) and total work during a 30-second Wingate test (MD 0.80 J•kg−1; 95% CI −2.44, 4.05; five studies). Thirteen studies involving 172 participants (age range 7–22 years) compared systemic β2-agonists with placebo, with 12 studies involving oral and one study involving intravenous salbutamol. A significant effect was detected for systemic β2-agonists on endurance time to exhaustion at 80–85% V̇O2max (MD 402 s; 95% CI 34, 770; two studies), but not for V̇O2max (placebo 42.5–1.7mL•kg−1•min−1, salbutamol 42.1±2.9mL•kg−1•min−1, one study), endurance time to exhaustion at 70% V̇O2max (MD 400 s; 95%CI −408, 1208; one study) or power output at 90% V̇O2max (placebo 234.9±16 W, salbutamol 235.5±18.1 W, one study). Asignificant effect was shown for systemic β2-agonists on peak power (MD 0.91 W•kg−1; 95% CI 0.25, 1.57; four studies), but not on total work (MD 7.8 J•kg−1; 95% CI −3.3, 18.9; four studies) during a 30-second Wingate test. There were no randomized controlled trials assessing the effects of systemic formoterol, salmeterol or terbutaline on physical performance. In conclusion, no significant effects were detected for inhaled β2-agonists on endurance, strength or sprint performance in healthy athletes. There is some evidence indicating that systemic β2-agonists may have a positive effect on physical performance in healthy subjects, but the evidence base is weak.
    Sports Medicine 01/2011; 41(1). DOI:10.2165/11537540-000000000-00000 · 5.32 Impact Factor
  • Source