Effects of Acute Ingestion of Salbutamol During Submaximal Exercise

Abstract

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.

Salbutamol effects on systemic potassium dynamics during and following intense continuous and intermittent exercise

“…Potassium clearance during exercise also occurs via uptake by other non-contracting or relatively inactive muscles, and also splanchnic K + uptake (Lindinger 1995;Sejersted and Sjøgaard 2000;Clausen 2003 (Hostrup et al 2014a;Collomp et al 2000;Grove et al 1995;Newnham et al 1993;Van Baak et al 2000), or in samples drawn only after completion of, rather than during exercise (Hostrup et al 2014a;Kalsen et al 2014;Hostrup et al 2014b;Larsson et al 1997;Grove et al 1995); and/or utilised oral salbutamol (Collomp et al 2000;Van Baak et al 2000;Hostrup et al 2014a;Goubault et al 2001 after prolonged cycling to exhaustion (Van Baak et al 2000), or at 5-10 min recovery after repeated 30 s sprints or repeated bouts of high intensity cycling, although greater reductions were evident at 1 or 2 min after some individual bouts (Hostrup et al 2014a). Similarly, after salbutamol inhalation (800 µg), there was no further change in antecubital venous [K + ] at 2-10 min after exhaustive cycling at 85% VO 2peak (Goubault et al 2001).…”

“…Salbutamol typically does not enhance performance during endurance exercise (Koch et al 2015;Pluim et al 2011), when K + disturbances are modest (Sejersted and Sjøgaard 2000), with some exceptions, where venous [K + ] was also reduced by ~0.2-0.4 mM (Van Baak et al 2000;Collomp et al 2000). Performance during a 30 s cycle sprint was enhanced by oral salbutamol (4-8 mg) (Le Panse et al 2007;Collomp et al 2005;Hostrup et al 2014a), with the post-exercise antecubital (Hostrup et al 2014a (Kalsen et al 2014).…”

“…Salbutamol lowers resting plasma [K + ], whether administered intravenously (Leitch et al 1976;Whyte et al 1987;Tobin et al 2006), by ingestion (Collomp et al 2000;Edner and Jogestrand 1990;Hostrup et al 2014a;Grove et al 1995) or inhalation (Lipworth et al 1989;Bennett and Tattersfield 1997;Clark and Lipworth 1996). However, salbutamol effects on [K + ] during intense exercise remain unclear, due to previous methodological limitations.…”

“…However, salbutamol effects on [K + ] during intense exercise remain unclear, due to previous methodological limitations. Firstly, interpretation is difficult from studies measuring only antecubital venous [K + ] (Hostrup et al 2014a;Collomp et al 2000;Grove et al 1995;Newnham et al 1993;Van Baak et al 2000), as this can underestimate arterial [K + ] by as much as 2 mM during intense exercise, due to substantial K + clearance by forearm muscles (Lindinger 1995;McKenna et al 1997;Lindinger et al 1995;Kowalchuk et al 1988). Secondly, numerous studies measured [K + ] in blood drawn only after completion of exercise (Hostrup et al 2014a;Kalsen et al 2014;Larsson et al 1997;Grove et al 1995;Hostrup et al 2014b), when plasma [K + ] is falling precipitously (McKenna et al 1997;Sejersted and Sjøgaard 2000).…”

Salbutamol intake and substrate oxidation during submaximal exercise

“…Due to the fear of the ergogenic doping effects demonstrated after both acute (Van Baak et al 2000;Collomp et al 2000aCollomp et al , 2002Le Panse et al 2007) and chronic (Collomp et al 2000b;Le Panse et al 2005 systemic abuse, the World antidoping agency (WADA) has put certain restrictions upon the use of beta-2 agonists and presently list four beta-agonists (i.e., salbutamol, terbutaline, formoterol and salmeterol) as a legal medication, permitted in the aerosol form only with a abbreviated therapeutic use exemption (TUE), whereas systemic use is completely banned.…”