TY - JOUR

T1 - Effect of formoterol, a long-acting β2-adrenergic agonist, on muscle strength and power output, metabolism and fatigue during maximal sprinting in men

AU - Kalsen, Anders

AU - Hostrup, Morten

AU - Backer, Vibeke

AU - Bangsbo, Jens

N1 - CURIS 2016 NEXS 155

PY - 2016

Y1 - 2016

N2 - The aim was to investigate the effect of the long-acting β2-adrenergic agonist formoterol on muscle strength and power output, muscle metabolism and phosphorylation of CaMKII Thr(287) and FXYD1 during maximal sprinting. In a double-blind crossover study, thirteen males (VO2max: 45.0±0.2 (mean±SE) mL min(-1) kg(-1)) performed a 30-s cycle ergometer sprint after inhalation of either 54 µg formoterol (FOR) or placebo (PLA). Before and after the sprint, muscle biopsies were collected from vastus lateralis and maximal voluntary contraction (MVC) and contractile properties of quadriceps were measured. Oxygen uptake was measured during the sprint. During the sprint, peak, mean and end power were 4.6±0.8, 3.9±1.1 and 9.5±3.2% higher (P<0.05) in FOR than in PLA, respectively. Net rates of glycogenolysis and glycolysis were 45.7±21.0 and 28.5±13.4% higher (P<0.05) in FOR than in PLA, respectively, and the decrease in ATP content was lower (P<0.05) in FOR than in PLA (3.7±1.5 vs. 8.0±1.6 mmol kg dw(-1)). There was no difference in breakdown of phosphocreatine and oxygen uptake between treatments. Before and after the sprint, MVC and peak twitch force were higher (P<0.05) in FOR than in PLA. No differences were observed in phosphorylation of CaMKII Thr(287) and FXYD1 between treatments before the sprint, whereas phosphorylation of CaMKII Thr(287) and FXYD1 was greater (P<0.05) in FOR than in PLA after the sprint. In conclusion, formoterol-induced enhancement in power output during maximal sprinting is associated with increased rates of glycogenolysis and glycolysis that may counteract development of fatigue.

AB - The aim was to investigate the effect of the long-acting β2-adrenergic agonist formoterol on muscle strength and power output, muscle metabolism and phosphorylation of CaMKII Thr(287) and FXYD1 during maximal sprinting. In a double-blind crossover study, thirteen males (VO2max: 45.0±0.2 (mean±SE) mL min(-1) kg(-1)) performed a 30-s cycle ergometer sprint after inhalation of either 54 µg formoterol (FOR) or placebo (PLA). Before and after the sprint, muscle biopsies were collected from vastus lateralis and maximal voluntary contraction (MVC) and contractile properties of quadriceps were measured. Oxygen uptake was measured during the sprint. During the sprint, peak, mean and end power were 4.6±0.8, 3.9±1.1 and 9.5±3.2% higher (P<0.05) in FOR than in PLA, respectively. Net rates of glycogenolysis and glycolysis were 45.7±21.0 and 28.5±13.4% higher (P<0.05) in FOR than in PLA, respectively, and the decrease in ATP content was lower (P<0.05) in FOR than in PLA (3.7±1.5 vs. 8.0±1.6 mmol kg dw(-1)). There was no difference in breakdown of phosphocreatine and oxygen uptake between treatments. Before and after the sprint, MVC and peak twitch force were higher (P<0.05) in FOR than in PLA. No differences were observed in phosphorylation of CaMKII Thr(287) and FXYD1 between treatments before the sprint, whereas phosphorylation of CaMKII Thr(287) and FXYD1 was greater (P<0.05) in FOR than in PLA after the sprint. In conclusion, formoterol-induced enhancement in power output during maximal sprinting is associated with increased rates of glycogenolysis and glycolysis that may counteract development of fatigue.

U2 - 10.1152/ajpregu.00364.2015

DO - 10.1152/ajpregu.00364.2015

M3 - Journal article

C2 - 27147617

VL - 310

SP - R1312-R1321

JO - American Journal of Physiology

JF - American Journal of Physiology

SN - 0363-6119

IS - 11

ER -