Effect of salbutamol on muscle strength and endurance performance in nonasthmatic men.
OBJECTIVE
The ergogenic effect of acute beta2-adrenergic agonist administration in nonasthmatic individuals has not been clearly demonstrated. Therefore, the acute effects of oral administration of the beta2-adrenergic agonist salbutamol (4 mg) on muscle strength and endurance performance were studied in 16 nonasthmatic men in a double-blind randomized cross-over study.


METHODS
Peak expiratory flow (Mini Wright Peakflowmeter), isokinetic strength of the knee extensors and knee flexors at four angular velocities (Cybex II dynamometer), and endurance performance in a cycle ergometer test until exhaustion at 70% of maximal workload were measured.


RESULTS
Peak expiratory flow increased from 601 +/- 67 L x min(-1) to 629 +/- 64 L x min(-1) after salbutamol (P < 0.05). Peak torque was higher after salbutamol than after placebo (4.4% for the knee extensors, 4.9% for the knee flexors) (P < 0.05). Mean endurance time increased from 3,039 +/- 1,031 s after placebo to 3,439 +/- 1,287 s after salbutamol (P = 0.19). When four subjects complaining about adverse side effects were excluded from the analysis, the increase in endurance time (729 +/- 1,007 s or 29%) was statistically significant (P <-0.05). Salbutamol did not affect VO2, respiratory exchange ratio, heart rate, and plasma free fatty acid and glycerol concentration during exercise; plasma lactate and potassium concentrations were increased (P < 0.05).


CONCLUSIONS
Under the conditions of this study, oral salbutamol appears to be an effective ergogenic aid in nonasthmatic individuals not experiencing adverse side effects.
Department of Human Biology, Maastricht University, The Netherlands. m.vanbaak@hb.unimaas.nL
M A
MA
van Baak
L H
LH
Mayer
R E
RE
Kempinski
F
F
Hartgens
D000284:Administration, Oral; D000328:Adult; D000420:Albuterol / Q000008:administration & dosage / Q000494:pharmacology*; D001993:Bronchodilator Agents / Q000008:administration & dosage / Q000494:pharmacology*; D004311:Double-Blind Method; D016552:Ergometry; D006339:Heart Rate; D006801:Humans; D019344:Lactic Acid / Q000032:analysis; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000502:physiology; D010807:Physical Endurance / Q000187:drug effects*; D011188:Potassium / Q000032:analysis
D001993:Bronchodilator Agents; D019344:Lactic Acid; D000420:Albuterol; D011188:Potassium