Mechanical, Biochemical, and Electromyographic Responses to Short-Term Eccentric–Concentric Knee Extensor Training in Humans

Váczi, Márk and Tihanyi, József and Hortobágyi, Tibor and Rácz, Levente and Csende, Zsolt and Costa, Andreas and Pucsok, József (2011) Mechanical, Biochemical, and Electromyographic Responses to Short-Term Eccentric–Concentric Knee Extensor Training in Humans. JOURNAL OF STRENGTH AND CONDITIONING RESEARCH, 25 (4). pp. 922-932. ISSN 1064-8011

Text Váczi JSCR 2011.pdf - Published Version Restricted to Registered users only Download (447kB)

Abstract

Váczi, M, Tihanyi, J, Hortobágyi, T, Rácz, L, Csende, Z, Costa, A, and Pucsok, J. Mechanical, biochemical, and electromyographic responses to short-term eccentric–concentric knee extensor training in humans. J Strength Cond Res 25(4): 922-932, 2011-This study examined the effects of short-term eccentric-concentric knee extensor training on mechanical and biochemical variables, myoelectric activity, and muscle soreness. Seventeen men were assigned to either experimental (E, n = 10) or control group (C, n = 7). Group E performed 90 maximal isokinetic eccentric-concentric knee extensor contractions on each of 3 consecutive days (Tr1-Tr3) followed by 1-day rest, and then on 4 more consecutive days (Tr4-Tr7). Peak eccentric torque of each contraction during the training was recorded and averaged for each session (MTr). Maximal isometric torque (M0), eccentric torque (Mecc), integrated electromyography (iEMG), plasma creatine kinase (CK), and lactate dehydrogenase (LDH) activities were measured before, immediately, 24, 48, and 72 hours after Tr1, at 1 and 3 days after Tr7. Group C did not train but performed all exercise tests; CK and LDH were measured at 3 time points only. Acutely, M0 and Mecc decreased and CK, LDH, and soreness increased more in E than in C 24 hours after Tr1. Chronically, MTr and M0 increased more in E than C by Tr7 and CK, LDH, and muscle soreness gradually decreased by Tr7 whereas iEMG increased more in E than in C after Tr3 through Tr7. High-intensity short-term eccentric-concentric knee extensor exercise training produced immediate reductions in maximal voluntary force. Most likely neural adaptations contributed to rapid recovery and strength adaptations because maximal voluntary force increased by the end of the training protocol in previously trained healthy adults.

Actions (login required)

View Item