title: Eccentric exercise: acute and chronic effects on healthy and diseased tendons.
abstract: Eccentric exercise can influence tendon mechanical properties and matrix protein synthesis. mRNA for collagen and regulatory factors thereof are upregulated in animal tendons, independent of muscular contraction type, supporting the view that tendon, compared with skeletal muscle, is less sensitive to differences in type and/or amount of mechanical stimulus with regard to expression of collagen, regulatory factors for collagen, and cross-link regulators. In overused (tendinopathic) human tendon, eccentric exercise training has a beneficial effect, but the mechanism by which this is elicited is unknown, and slow concentric loading appears to have similar beneficial effects. It may be that tendinopathic regions, as long as they are subjected to a certain magnitude of load at a slow speed, independent of whether this is eccentric or concentric in nature, can reestablish their normal tendon fibril alignment and cell morphology.
authors.affiliation: Institute of Sports Medicine, Department of Orthopedic Surgery M, Bispebjerg Hospital, and Center for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Michael
authors.initials: M
authors.lastname: Kjaer
authors.affiliation: Institute of Sports Medicine, Department of Orthopedic Surgery M, Bispebjerg Hospital, and Center for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark Katjaheinemeier@gmail.com.
authors.forename: Katja M
authors.initials: KM
authors.lastname: Heinemeier
mesh_terms: D055119:Elastic Modulus; D019317:Evidence-Based Medicine; D005081:Exercise Therapy / Q000379:methods*; D006801:Humans; D052256:Tendinopathy / Q000503:physiopathology* / Q000534:rehabilitation*; D013710:Tendons / Q000503:physiopathology*; D013718:Tensile Strength; D016896:Treatment Outcome
keywords: extracellular matrix; tendinitis; tendinosis