title: Muscle force recovery in relation to muscle oxygenation.
abstract: The aim of this study was to investigate the relative contribution of human muscle reoxygenation on force recovery following a maximal voluntary contraction (MVC). Ten athletes (22·9 ± 4·0 years) executed a plantar-flexion sequence including two repeated MVCs [i.e. a 30-s MVC (MVC(30)) followed by a 10-s MVC (MVC(10))] separated by 10, 30, 60, 120 or 300 s of passive recovery. A 10-min passive recovery period was allowed between each MVC sequence. This procedure was randomly repeated with two different recovery conditions: without (CON) or with (OCC) arterial occlusion of the medial gastrocnemius. During OCC, the occlusion was maintained from the end of MVC(30) to the end of MVC(10). Muscle oxygenation (Near-infrared spectroscopy, NIRS, [Hb(diff) ]) was continuously measured during all MVC sequences and expressed as a percentage of the maximal changes in optical density observed during MVC(30). Maximal Torque was analysed at the start of each contraction. Torque during each MVC(10) was expressed as a percentage of the Torque during the previous MVC(30). Torque recovery was complete within 300 s after MVC(30) during CON (MVC(10) = 101·8 ± 5·0%); 88·6 ± 8·9% of the Torque was recovered during OCC (P = 0·005). There was also a moderate correlation between absolute level of muscle oxygenation and Torque (r = 0·32 (90% CI, 0·09;0·52), P = 0·02). Present findings confirm the role of human muscle oxygenation in muscular force recovery during repeated-maximal efforts. However, the correlation between absolute muscle oxygenation and force level during recovery is only moderate, suggesting that other mechanisms are likely involved in the force recovery process.
authors.affiliation: Faculty of Sport Sciences, Laboratory of Exercise Physiology and Rehabilitation, University of Picardie Jules Verne, Amiens, France. pierreufland@gmail.com
authors.forename: Pierre
authors.initials: P
authors.lastname: Ufland
authors.forename: Thomas
authors.initials: T
authors.lastname: Lapole
authors.forename: Said
authors.initials: S
authors.lastname: Ahmaidi
authors.forename: Martin
authors.initials: M
authors.lastname: Buchheit
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001696:Biomechanical Phenomena; D006801:Humans; D007511:Ischemia / Q000378:metabolism / Q000503:physiopathology; D008297:Male; D009119:Muscle Contraction; D053580:Muscle Strength; D018482:Muscle, Skeletal / Q000098:blood supply / Q000378:metabolism* / Q000503:physiopathology; D010100:Oxygen / Q000097:blood*; D010101:Oxygen Consumption; D011780:Qatar; D020127:Recovery of Function; D012039:Regional Blood Flow; D019265:Spectroscopy, Near-Infrared; D013997:Time Factors; D019415:Torque; D014111:Tourniquets; D055815:Young Adult
chemical_list: D010100:Oxygen