title: Differential effects of exhaustive cycle ergometry on concentric and eccentric torque production.
abstract: The purpose of this study was to investigate the potential differences in peak isokinetic concentric end eccentric torque following low- and high-intensity cycle exercise fatigue protocols. Ten healthy, recreationally-active men were tested in a balanced, randomized testing sequence for peak eccentric and concentric isokinetic torque (60 degrees/sec) immediately before and after three experimental conditions each separated by 48 hours: 1) a bout of high intensity cycling consisting of a maximal 90-second sprint; 2) a bout of low-intensity cycling at 60 rpm equated for total work with the high-intensity protocol: and 3) no exercise (control bout). Blood was drawn from an antecubital vein and plasma lactate concentrations were determined immediately before and after each experimental bout. Post-exercise plasma lactate concentrations were 15.1 +/- 2.5 and 4.7 +/- 1.9 mmol l(-1), respectively, following the high- and low-intensity protocols. The high intensity exercise bout resulted in the only post-exercise decrease in concentric and eccentric isokinetic peak torque. The percent decline in maximal force production was significantly (P< 0.05) greater for concentric muscle actions compared to eccentric (29 vs 15%, respectively). In conclusion, a 90-second maximal cycling sprint results in a significant decline in maximal torque of both concentric and eccentric muscle actions with the greatest magnitude observed during concentric muscle actions.
authors.affiliation: Human Performance Laboratory, University of Connecticut, Storrs, USA.
authors.forename: W J
authors.initials: WJ
authors.lastname: Kraemer
authors.forename: D F
authors.initials: DF
authors.lastname: Gardiner
authors.forename: S E
authors.initials: SE
authors.lastname: Gordon
authors.forename: L P
authors.initials: LP
authors.lastname: Koziris
authors.forename: W
authors.initials: W
authors.lastname: Sebastianelli
authors.forename: M
authors.initials: M
authors.lastname: Putukian
authors.forename: R U
authors.initials: RU
authors.lastname: Newton
authors.forename: N A
authors.initials: NA
authors.lastname: Ratamess
authors.forename: J S
authors.initials: JS
authors.lastname: Volek
authors.forename: K
authors.initials: K
authors.lastname: Häkkinen
mesh_terms: D000328:Adult; D018592:Cross-Over Studies; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test / Q000379:methods*; D006801:Humans; D007717:Knee / Q000502:physiology; D019344:Lactic Acid / Q000097:blood; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D018763:Muscle Fatigue / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D010806:Physical Education and Training / Q000379:methods; D019415:Torque
chemical_list: D019344:Lactic Acid