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.
van Baak
M A
MA
Department of Human Biology, Maastricht University, The Netherlands. m.vanbaak@hb.unimaas.nL
Mayer
L H
LH
Kempinski
R E
RE
Hartgens
F
F
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