Abstract

The acute effects of inhaled albuterol, a selective beta-2 adrenergic agonist, on measures of endurance cycling performance and pulmonary function were assessed in 21 competitive road cyclists, all non-asthmatics. Albuterol (A) total dose 360 micro-g or a saline placebo (P) was administered by inhaler, in 4 metered doses of 90 micro-g each, 15 minutes before cycle ergometry exercise. Heart rate, whole blood lactate, perceived exertion and VO2 were determined at the submaximal workloads of 150, 200, 225, 250, 275, 300 watts and at max. Pulmonary function tests determining forced vital capacity, forced expiratory volume during the first second of expiration, forced mid-expiratory flow and maximal voluntary ventilation were performed prior to and 10 minutes after inhalation; and 5, 10 and 15 minutes after termination of the exercise protocol. Heart rate was significantly greater during the A compared to the P treatment at 200 (150.8+-2.5 vs 146.7+-2.8 beats/min), 225 (159.7+-2.4 vs 154.6+-2.7) and 250 watts (166.9+-2.4 vs 164.4+-2.6). Whole blood lactate was significantly greater during the A compared to the P treatment at 275 watts (4.7+-0.3 vs 4.2+-0.4 mmol/l). No other significant differences were found between the 2 treatments at any time point. These data indicate that the acute effect of albuterol inhalation at twice the recommended dosage has no positive effect on endurance performance measures of pulmonary function in athletes who are not asthmatic. Verf.-Referat