Effects of short-term oral salbutamol administration on exercise endurance and metabolism.
The present study examined whether oral short-term administration of salbutamol (Sal) modifies performance and selected hormonal and metabolic variables during submaximal exercise. Eight recreational male athletes completed two cycling trials at 80-85% peak O(2) consumption until exhaustion after either gelatin placebo (Pla) or oral Sal (12 mg/day for 3 wk) treatment, according to a double-blind and randomized protocol. Blood samples were collected at rest, after 5, 10, and 15 min, and at exhaustion to determine growth hormone (GH), cortisol, testosterone, triiodothyronine (T(3)), C peptide, free fatty acid (FFA), blood glucose, lactate, and blood urea values. Time of cycling was significantly increased after chronic Sal intake (Sal: 30.5 +/- 3.1 vs. Pla: 23.7 +/- 1.6 min, P < 0.05). No change in any variable was found before cycling except a decrease in blood urea concentration and an increase in T(3) after Sal that remained significant throughout the exercise test (P < 0.05). Compared with rest, exercise resulted in a significant increase in GH, cortisol, testosterone, T(3), FFAs, and lactate and a decrease in C peptide after both treatments with higher exercise FFA levels and exhaustion GH concentrations after Sal (P < 0.05). Sal but not Pla significantly decreased exercise blood glucose levels. From these data, short-term Sal intake did appear to improve performance during intense submaximal exercise with concomitant increase in substrate availability and utilization, but the exact mechanisms involved need further investigation.
Laboratoire National de Dépistage du Dopage, Chatenay-Malabry, France. LNDD.FRANCE@wanadoo.fr
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K
Collomp
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R
Candau
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Lasne
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Labsy
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Préfaut
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J
De Ceaurriz
D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000328:Adult; D000420:Albuterol / Q000494:pharmacology*; D001786:Blood Glucose / Q000378:metabolism; D001806:Blood Urea Nitrogen; D018592:Cross-Over Studies; D004311:Double-Blind Method; D015444:Exercise / Q000502:physiology*; D005230:Fatty Acids, Nonesterified / Q000097:blood; D006728:Hormones / Q000097:blood; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D008660:Metabolism / Q000187:drug effects*; D010807:Physical Endurance / Q000187:drug effects*
D000318:Adrenergic beta-Agonists; D001786:Blood Glucose; D005230:Fatty Acids, Nonesterified; D006728:Hormones; D019344:Lactic Acid; D000420:Albuterol