title: Improvements in multi-joint leg function following chronic eccentric exercise.
abstract: Previous authors have reported that chronic eccentric cycling facilitates greater changes in multi-joint leg function (hopping frequency, maximum jumping height) compared with concentric cycling. Our purpose was to evaluate changes in leg spring stiffness and maximum power following eccentric and concentric cycling training. Twelve individuals performed either eccentric (n=6) or concentric (n=6) cycling for 7 weeks (3 sessions/week) while training duration progressively increased. Participants performed trials of submaximal hopping, maximal counter movement jumps, and maximal concentric cycling to evaluate leg spring stiffness, maximum jumping power, and maximum concentric cycling power respectively, before and 1 week following training. Total work during training did not differ between eccentric and concentric cycling (126 ± 15-728 ± 91 kJ vs 125 ± 10-787 ± 76 kJ). Following training, eccentric cycling exhibited greater changes in k(leg) and jumping P(max) compared with CON(cyc) (10 ± 3% vs -2 ± 4% and 7 ± 2% vs -2 ± 3%, respectively, P=0.05). Alterations in CON(cyc) P(max) did not differ between ECC(cyc) (1035 ± 142 vs 1030 ± 133 W) and CON(cyc) (1072 ± 98 vs 1081 ± 85 W). These data demonstrate that eccentric cycling is an effective method for improving leg spring stiffness and maximum power during multi-joint tasks that include stretch-shortening cycles. Improvements in leg spring stiffness and maximum power would be beneficial for both aging and athletic populations.
authors.affiliation: Department of Exercise and Sport Science, The University of Utah, Salt Lake City, Utah, USA. steve.elmer@utah.edu
authors.forename: S
authors.initials: S
authors.lastname: Elmer
authors.forename: S
authors.initials: S
authors.lastname: Hahn
authors.forename: P
authors.initials: P
authors.lastname: McAllister
authors.forename: C
authors.initials: C
authors.lastname: Leong
authors.forename: J
authors.initials: J
authors.lastname: Martin
mesh_terms: D000222:Adaptation, Physiological; D000328:Adult; D000704:Analysis of Variance; D001642:Bicycling / Q000502:physiology*; D016552:Ergometry; D015444:Exercise / Q000502:physiology*; D005081:Exercise Therapy; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology; D007866:Leg / Q000502:physiology*; D008297:Male; D018763:Muscle Fatigue / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D013997:Time Factors