Effect of cold exposure (-15 degrees C) and salbutamol treatment on physical performance in elite nonasthmatic cross-country skiers.
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.
Sandsund
M
M
SINTEF Unimed, Division of Extreme Work Environment, Trondheim, Norway.
Sue-Chu
M
M
Helgerud
J
J
Reinertsen
R E
RE
Bjermer
L
L
D000280:Administration, Inhalation; D000318:Adrenergic beta-Agonists / Q000008:administration & dosage / Q000494:pharmacology*; D000328:Adult; D000332:Aerobiosis / Q000187:drug effects / Q000502:physiology; D000420:Albuterol / Q000008:administration & dosage / Q000494:pharmacology*; D003081:Cold Climate / Q000009:adverse effects*; D018592:Cross-Over Studies; D004300:Doping in Sports; D004311:Double-Blind Method; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005541:Forced Expiratory Volume / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D010101:Oxygen Consumption / Q000187:drug effects; D010807:Physical Endurance / Q000187:drug effects / Q000502:physiology; D012865:Skiing / Q000502:physiology*; D013696:Temperature
D000318:Adrenergic beta-Agonists; D019344:Lactic Acid; D000420:Albuterol