To assess the eventual effects of acute oral salbutamol intake on performance and metabolism during submaximal exercise, nine healthy volunteers completed two cycling trials at a power corresponding to 80-85% VO2max, after either placebo (Pla) or salbutamol (Sal, 6 mg) treatment, according to a double-blind randomized protocol. Blood samples were collected both at rest and during exercise (5 min-, 10 min-, 15 min-exhaustion) for C-peptide, FFA, lactate and blood glucose measurements. Cycling performance was significantly improved in the Sal vs. Pla trials (p < 0.05). After Sal intake, resting C-peptide, lactate, FFA and blood glucose values were higher whereas exercise lactate and free fatty acid concentrations were greater during and at the conclusion of the exercise period (p < 0.05). These results suggest that acute salbutamol ingestion improved performance during submaximal exercise probably through an enhancement of the overall contribution to energy production from both aerobic and anaerobic metabolisms.

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.

Competitive swimmers regularly perform apnea series with or without fins as part of their training, but the ergogenic and metabolic repercussions of acute and chronic apnea have not been examined. Therefore, we aimed to investigate the cardiovascular, lactate, arterial oxygen saturation and hormonal responses to acute apnea in relation to performance in male swimmers. According to a randomized protocol, 15 national or regional competitive swimmers were monitored while performing four 100-m freestyle trials, each consisting of four 25-m segments with departure every 30 seconds at maximal speed in the following conditions: with normal frequency breathing with fins (F) and without fins (S) and with complete apnea for the four 25-m segments with (FAp) and without fins (SAp). Heart rate (HR) was measured continuously and arterial oxygen saturation, blood, and saliva samples were assessed after 30 seconds, 3 minutes, and 10 minutes of recovery, respectively. Swimming performance was better with fins than without both with normal frequency breathing and apnea (p < 0.001). Apnea induced no change in lactatemia, but a decrease in arterial oxygen saturation in both SAp and FAp (p < 0.001) was noted and a decrease in HR and swimming performance in SAp (p < 0.01). During apnea without fins, performance alteration was correlated with bradycardia (r = 0.63) and arterial oxygen desaturation (r = -0.57). Saliva dehydroepiandrosterone was increased compared with basal values whatever the trial (p ≤ 0.05), whereas no change was found in saliva cortisol or testosterone. Further studies are necessary to clarify the fin effect on HR and performance during apnea swimming.

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