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.
Collomp
K
K
Laboratoire National de Dépistage du Dopage, Chatenay-Malabry, France. LNDD.FRANCE@wanadoo.fr
Candau
R
R
Lasne
F
F
Labsy
Z
Z
Préfaut
C
C
De Ceaurriz
J
J
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