title: Associated decrements in rate of force development and neural drive after maximal eccentric exercise.
abstract: The present study investigated the changes in contractile rate of force development (RFD) and the neural drive following a single bout of eccentric exercise. Twenty-four subjects performed 15 × 10 maximal isokinetic eccentric knee extensor contractions. Prior to and at 24, 48, 72, 96, and 168 h during post-exercise recovery, isometric RFD (30, 50 100, and 200 ms), normalized RFD [1/6,1/2, and 2/3 of maximal voluntary contraction (MVC)] and rate of electromyography rise (RER; 30, 50, and 75 ms) were measured. RFD decreased by 28-42% peaking at 48 h (P < 0.01-P < 0.001) and remained depressed at 168 h (P < 0.05). Normalized RFD at 2/3 of MVC decreased by 22-39% (P < 0.01), peaked at 72 h and returned to baseline at 168 h. These changes in RFD were associated with a decrease in RER at 48 h-96 h (P < 0.05-P < 0.001). Accumulated changes (area under curve) revealed a greater relative decrease in accumulated RFD at 100 ms by -2727 ± 309 (%h; P < 0.05) and 200 ms by -3035 ± 271 (%h; P < 0.001) compared with MVC, which decreased, by -1956 ± 234 (%h). In conclusion, RFD and RER are both markedly reduced following a bout of maximal eccentric exercise. This association suggests that exercise-induced decrements in RFD can, in part, be explained decrements in neural drive.
authors.affiliation: Section for Sports Science, Department of Public Health, Aarhus University, Aarhus, Denmark.
authors.forename: J
authors.initials: J
authors.lastname: Farup
authors.affiliation: Section for Sports Science, Department of Public Health, Aarhus University, Aarhus, Denmark.
authors.forename: S K
authors.initials: SK
authors.lastname: Rahbek
authors.affiliation: Section for Sports Science, Department of Public Health, Aarhus University, Aarhus, Denmark.
authors.forename: J
authors.initials: J
authors.lastname: Bjerre
authors.affiliation: Department of Biomedicine, Aarhus University, Aarhus, Denmark.
authors.forename: F
authors.initials: F
authors.lastname: de Paoli
authors.affiliation: Section for Sports Science, Department of Public Health, Aarhus University, Aarhus, Denmark.
authors.forename: K
authors.initials: K
authors.lastname: Vissing
mesh_terms: D004576:Electromyography; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D006801:Humans; D008297:Male; D009119:Muscle Contraction; D053580:Muscle Strength; D052097:Quadriceps Muscle / Q000502:physiology*; D013997:Time Factors; D019415:Torque; D055815:Young Adult
keywords: Eccentric exercise; maximal voluntary contraction force; rate of electromyography rise