title: Metformin improves performance in high-intensity exercise, but not anaerobic capacity in healthy male subjects.
abstract: The aim of this study was to determine the ergogenic effects of metformin in high-intensity exercise, as well as its effects on anaerobic capacity, in healthy and physically active men. Ten subjects (mean (± standard deviation) maximal oxygen uptake (V˙O2max ) 38.6 ± 4.5 mL/kg per min) performed the following tests in a cycle ergometer: (i) an incremental test; (ii) six submaximal constant workload tests at 40%-90% (V˙O2max ); and (iii) two supramaximal tests (110% (V˙O2max ). Metformin (500 mg) or placebo was ingested 60 min before the supramaximal test. There were no significant differences between the placebo and metformin groups in terms of maximum accumulated oxygen deficit (2.8 ± 0.6 vs 3.0 ± 0.8 L, respectively; P = 0.08), lactate concentrations (7.8 ± 2.6 vs 7.5 ± 3.0 mmol/L, respectively; P = 0.75) or O2 consumed in either the last 30 s of exercise (40.4 ± 4.4 vs 39.9 ± 4.0 mL/kg per min, respectively; P = 0.35) or the first 110 s of exercise (29.0 ± 2.5 vs 29.5 ± 3.0 mL/kg per min, respectively; P = 0.42). Time to exhaustion was significantly higher after metformin than placebo ingestion (191 ± 33 vs 167 ± 32 s, respectively; P = 0.001). The fast component of V˙O2 recovery was higher in the metformin than placebo group (12.71 vs 12.18 mL/kg per min, respectively; P = 0.025). Metformin improved performance and anaerobic alactic contribution during high-intensity exercise, but had no effect on overall anaerobic capacity in healthy subjects.
authors.affiliation: Laboratory of Physical Fitness, Performance and Health, Experimental Nutrition Laboratory, Sport Science Research Group, PPGNUT/Physical Education, Federal University of Alagoas, Maceio, Brazil.
authors.forename: S K
authors.initials: SK
authors.lastname: Learsi
authors.affiliation: Laboratory of Physical Fitness, Performance and Health, Experimental Nutrition Laboratory, Sport Science Research Group, PPGNUT/Physical Education, Federal University of Alagoas, Maceio, Brazil.
authors.forename: V J
authors.initials: VJ
authors.lastname: Bastos-Silva
authors.affiliation: Sport Science Research Group, Federal University of Pernambuco, Vitoria de Santo Antao, Brazil.
authors.forename: A E
authors.initials: AE
authors.lastname: Lima-Silva
authors.affiliation: Endurance Performance Research Group, University of Sao Paulo, Sao Paulo, Brazil.
authors.forename: R
authors.initials: R
authors.lastname: Bertuzzi
authors.affiliation: Laboratory of Physical Fitness, Performance and Health, Experimental Nutrition Laboratory, Sport Science Research Group, PPGNUT/Physical Education, Federal University of Alagoas, Maceio, Brazil.
authors.forename: G G
authors.initials: GG
authors.lastname: De Araujo
mesh_terms: D000255:Adenosine Triphosphate / Q000096:biosynthesis; D000693:Anaerobiosis / Q000187:drug effects; D004734:Energy Metabolism / Q000187:drug effects; D015444:Exercise / Q000502:physiology*; D006019:Glycolysis / Q000187:drug effects; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D008687:Metformin / Q000494:pharmacology*; D009119:Muscle Contraction / Q000187:drug effects; D010101:Oxygen Consumption / Q000187:drug effects; D058573:Performance-Enhancing Substances / Q000494:pharmacology*; D055815:Young Adult
chemical_list: D058573:Performance-Enhancing Substances; D000255:Adenosine Triphosphate; D008687:Metformin
keywords: ADP; AMP-activated protein kinases; biguanides; energy metabolism; exercise; glucose transporter type 4; glycolysis; oxygen consumption