Inhaled Salbutamol and Endurance Cycling Performance in Non-Asthmatic Athletes

Abstract

Beta₂-adrenergic agonists are important therapeutic agents for the prevention and treatment of (exercise-induced) asthma in athletes, but may have ergogenic effects. In this study we investigated whether inhalation of a supra-therapeutic dose of 800 µg salbutamol before exercise affects endurance performance during a cycling trial in non-asthmatic athletes. In a double-blind, randomized cross-over study, 16 athletes performed two trials, where they had to perform a certain amount of work as fast as possible on a cycle ergometer, 30 minutes after inhalation of 800 µg salbutamol or placebo. Peak expiratory flow (PEF), forced vital capacity (FVC), and forced expiratory volume in 1 second (FEV₁) were measured before and after exercise and blood samples were obtained before and during exercise. Cycling performance time was 4010.2 ± 327.7 s after placebo inhalation and 3927.6 ± 231.3 s after inhalation salbutamol (p < 0.05). Although salbutamol inhalation increased plasma free fatty acids, glycerol and lactate concentrations and decreased plasma potassium concentrations at rest, no differences between placebo and salbutamol in these variables were found during exercise. PEF and FEV₁ were increased after salbutamol inhalation at rest compared with placebo, but the difference between placebo and salbutamol after exercise was no longer significant. Inhalation of a supratherapeutic dose of 800 µg salbutamol improved endurance cycling performance by 1.9 ± 1.8 % in non-asthmatic athletes, which indicates that this route of administration does not exclude the possibility of an ergogenic effect of beta₂-adrenergic agents in athletes. The increase in performance was not explained by changes in plasma concentrations of free fatty acids, glycerol, lactate, and potassium during exercise or by changes in ventilatory parameters at rest and after exercise. Therefore, the mechanism of the increase in performance remains to be determined.

Key words

Ventilation - free fatty acids - glycerol - lactate - potassium - ergogenic effect

References

• 1 Bedi F, Gong H, Horvath S M. Enhancement of exercise performance with inhaled albuterol.  Can J Sport Sci. 1988;  13 144-148
• 2 Carlsen K-H, Ingjer F, Kirkegaard H, Thyness B. The effect of inhaled salbutamol on lung function and endurance performance in healthy well-trained athletes.  Scand J Med Sci Sports. 1997;  7 160-165
• 3 Carlsen K-H, Hem E, Stensrud T, Held T, Herland K, Mowinckel P. Can asthma treatment in sports be doping? The effect of the rapid onset, long-acting inhaled β₂-agonist formoterol upon endurance performance in healthy well-trained athletes.  Resp Med. 2001;  95 571-576
• 4 Collomp K, Candau R, Collomp R, Carra J, Lasne F, Préfaut C, De Ceaurriz J. Effects of acute ingestion of salbutamol during submaximal exercise.  Int J Sports Med. 2000;  21 480-484
• 5 Collomp K, Candau R, Lasne F, Labsy Z, Préfaut C, De Ceaurriz J. Effects of short-term oral salbutamol administration on exercise endurance and metabolism.  J Appl Physiol. 2000;  80 430-436
• 6 Dempsey J A, Wagner P D. Exercise-induced arterial hypoxemia.  J Appl Physiol. 1999;  87 1997-2006
• 7 Fleck S J, Lucia A, Storms W W, Wallach J M, Vint P F, Zimmerman S D. Effects of acute inhalation of albuterol on submaximal and maximal VO₂ and blood lactate.  Int J Sports Med. 1993;  14 239-243
• 8 Freeman W, Packe G E, Cayton R M. Effect of nebulised salbutamol on maximal exercise performance in men with mild asthma.  Thorax. 1989;  44 942-947
• 9 Goubault C, Peraul M-C, Leleu E, Bouquet S, Legros P, Vandel B, Denjean A. Effects of inhaled salbutamol in exercising non-asthmatic athletes.  Thorax. 2001;  56 675-679
• 10 Grove A, McFarlane L C, Lipworth B J. Expression of the β₂ adrenoceptor partial agonist/antagonist activity of salbutamol in states of low and high adrenergic tome.  Thorax. 1995;  50 134-138
• 11 Gutmann I, Wahlefeld A W. L-(+)-Lactate determination with lactate dehydrogenase and NAD. Bergmeyer MU Methods in Enzymatic Analysis. New York; Academic Press 1974: 1464-1468
• 12 Heir T, Stemshaug H. Salbutamol and high-intensity treadmill running in nonasthmatic highly conditioned athletes.  Scand J Med Sci Sports Exerc. 1995;  5 231-236
• 13 Hoffman B B, Lefkowitz R J. Catecholamines, sympathomimetic drugs, and adrenergic receptor antagonists. Molinoff PB, Ruddon RW Goodman & Gilman's The Pharmacological Basis of Therapeutics. 9th ed. New York; McGraw-Hill 1996: 199-248
• 14 International Olympic Committee .Olympic Movement Anti-Doping Code. List of prohibited classes of substances and prohibited methods 2001 - 2002. Lausanne; International Olympic Committee 2001
• 15 Jeukendrup A E, Saris W HM, Brouns F, Kester A DM. A new validated endurance performance test.  Med Sci Sports Exerc. 1996;  28 266-270
• 16 Johnson R J. Exercise-induced asthma. Sallis RE, Massimo F ACSM's Essentials of Sports Medicine. St Louis; Mosby 1997: 64-68
• 17 Kuipers H, Verstappen F TJ, Keizer H A, Geurten P, van Kranenburg G. Variability of aerobic performance in the laboratory and its physiologic correlates.  Int J Sports Med. 1985;  6 197-201
• 18 Larsson K, Gavhed D, Larsson L, Holmér I, Jorfeldt L, Ohlsén P. Influence of a β₂-agonist on physical performance at low temperatures in elite athletes.  Med Sci Sports Exerc. 1997;  29 1631-1636
• 19 Lemmer J T, Fleck S J, Wallach J M, Fox S, Burke E R, Kearney J T, Storms W W. The effects of albuterol on power output in non-asthmatic athletes.  Int J Sports Med. 1995;  16 243-249
• 20 Martineau L, Horan M A, Rothwell N J, Little R A. Salbutamol, a β₂-adrenoceptor agonist, increases skeletal muscle strength in young men.  Clin Sci. 1992;  83 615-621
• 21 Matthys D, Calders P, Pannier J L. Inhaled salbutamol decreases blood ammonia levels during exercise in normal subjects.  Eur J Appl Physiol. 1998;  79 110-113
• 22 McDowell S L, Fleck S J, Storms W W. The effects of salmeterol on power output in nonasthmatic athletes.  J Allergy Clin Immunol. 1997;  99 443-449
• 23 McKenzie D C, Rhodes E C, Stirling D R, Wiley J P, Dunwoody D W, Filsinger I B, Jang F, Stevens A. Salbutamol and treadmill performance in non-atopic athletes.  Med Sci Sports Exerc. 1983;  15 520-522
• 24 Meeuwisse W H, McKenzie D C, Hopkins S R, Road J D. The effect of salbutamol on performance in elite nonasthmatic athletes.  Med Sci Sports Exerc. 1992;  24 1161-1166
• 25 Morton A R, Papalia S M, Fitch K D. Is salbutamol ergogenic? The effects of salbutamol on physical performance in high-performance nonasthmatic athletes.  Clin J Sports Med. 1992;  2 93-97
• 26 Norris S R, Petersen S R, Jones R L. The effect of salbutamol on performance in endurance cyclists.  Eur J Appl Physiol. 1996;  73 364-368
• 27 Price A H, Clissold S P. Salbutamol in the 1980 s. A reappraisal of its clinical efficacy.  Drugs. 1989;  38 77-122
• 28 Sandsund M, Sue-Chu M, Helgerud J, Reinertsen R E, Bjermer L. Effect of cold exposure (- 15 °C) and salbutamol treatment on physical performance in elite nonasthmatic cross-country skiers.  Eur J Appl Physiol. 1998;  77 297-304
• 29 Signorile J F, Kaplan T A, Applegate B, Perry A C. Effects of acute inhalation of the bronchodilator, albuterol, on power output.  Med Sci Sports Exerc. 1992;  24 638-642
• 30 Sjøgaard G. Exercise-induced muscle fatigue: the significance of potassium.  Acta Physiol Scand. 1990;  593 (Suppl) 1-43
• 31 Van Baak M A, Mayer L HJ, Kempinski R ES, Hartgens F. Effect of salbutamol on muscle strength and endurance performance in nonasthmatic men.  Med Sci Sports Exerc. 2000;  32 1300-1306
• 32 Violante B, Pellegrino R, Vinay C, Selleri R, Ghinamo G. Failure of aminophylline and salbutamol to improve respiratory muscle function and exercise tolerance in healthy humans.  Respiration. 1989;  55 227-236