title: Concomitant changes in cross-sectional area and water content in skeletal muscle after resistance exercise.
abstract: This study investigated how one bout (1EX) and three bouts (3EX) of strenuous resistance exercise affected the cross-sectional area (CSA) and water content (WC) of the quadriceps muscle and patella tendon (PT), 4 h and 52 h after the last exercise bout. Ten healthy untrained male subjects performed 1EX with one leg and 3EX with the other leg. CSA and WC were measured with magnetic resonance imaging 10, 20 and 30 cm proximal to the tibia plateau (TP) for the muscle, and at the proximal, central and distal site for the PT prior to exercise, and 4 h and 52 h after the last exercise bout. Ten centimeter above the TP, muscle CSA was significantly increased at 4 h (1EX: 13 ± 5%; 3EX: 13 ± 4%) and 52 h (1EX: 16 ± 5%; 3EX: 16 ± 5%) compared with baseline. Muscle WC was significantly increased at 4 h (1EX: 7 ± 1%; 3EX: 6 ± 2%) and 52 h (1EX: 8 ± 2%; 3EX: 8 ± 3%) compared to baseline. PT central CSA was significantly reduced at 52 h (3EX: 14 ± 2%) compared with baseline and (3EX: 13 ± 1%) compared with 4 h. Present data demonstrate that strenuous resistance exercise results in an acute increase in muscle WC and underlines the importance of ensuring sufficient time between the last exercise bout and the determination of anatomical dimensions in muscles.
authors: Institute of Sports Medicine, Department of Orthopedic Surgery M, Bispebjerg Hospital and Center for Healthy Ageing, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark.
authors: M S
authors: MS
authors: Kristiansen
authors: Section of Sports Science, Department of Public Health, Aarhus University, Aarhus, Denmark.
authors: A
authors: A
authors: Uhrbrand
authors: Institute of Sports Medicine, Department of Orthopedic Surgery M, Bispebjerg Hospital and Center for Healthy Ageing, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark.|Section of Sports Science, Department of Public Health, Aarhus University, Aarhus, Denmark.
authors: M
authors: M
authors: Hansen
authors: Children's Orthopedic Department E, Aarhus University Hospital NBG and Orthopedic Research Laboratory, Aarhus University, Aarhus, Denmark.
authors: J M
authors: JM
authors: Shiguetomi-Medina
authors: Section of Sports Science, Department of Public Health, Aarhus University, Aarhus, Denmark.
authors: K
authors: K
authors: Vissing
authors: The MR Research Center, Aarhus University Hospital Skejby, Aarhus, Denmark.
authors: H
authors: H
authors: Stødkilde-Jørgensen
authors: Institute of Sports Medicine, Department of Orthopedic Surgery M, Bispebjerg Hospital and Center for Healthy Ageing, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark.|CopenRehab, Institute of Social Medicine, Department of Public Health and Centre for Healthy Ageing, Faculty of Heath Sciences, University of Copenhagen, Copenhagen, Denmark.
authors: H
authors: H
authors: Langberg
mesh_terms: D000328:Adult; D001834:Body Water / Q000378:metabolism*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D053580:Muscle Strength; D017847:Patellar Ligament / Q000033:anatomy & histology; D005082:Physical Exertion / Q000502:physiology*; D052097:Quadriceps Muscle / Q000033:anatomy & histology* / Q000502:physiology*; D055070:Resistance Training / Q000379:methods; D013997:Time Factors; D055815:Young Adult
keywords: Resistance training; Siswin; acute; connective tissue; heavy load; magnetic resonance imaging; strength training