Strength gain through eccentric isotonic training without changes in clinical signs or blood markers

Abstract

BackgroundLocalized exercises are widely used in rehabilitation processes. The predominant options are exercises with an emphasis on either concentric or eccentric contractions. Eccentric exercises promote greater strength gains compared to classical concentric stimuli, but can cause muscle damage. The aim of present study was to compare strength training composed of 10 sessions with progressive loads between groups with a predominance of concentric versus eccentric contraction through an analysis of isotonic strength, pressure pain threshold, creatine kinase, tumor necrosis factor-alpha and cortisol.MethodsOne hundred twenty male subjects were divided into four groups: C1 and E1 – single session of maximum strength with emphasis on concentric and eccentric contraction, respectively; C10 and E10 – 10 sessions with progressive loads from 80% to maximum strength with emphasis on concentric and eccentric contraction, respectively.ResultsIsotonic strength increased by 10% in E10 following the ten training sessions. C1 and E1 exhibited a lower pressure pain threshold 48 hours after the sessions in comparison to C10 and E10, respectively. Creatine kinase was increased in C1 in comparison to baseline, with significant differences (p ≤ 0.05) in comparison to E1 at 48 and 96 hours as well as C10 at 48, 72 and 96 hours. No significant differences were found in TNF-α or cortisol among the groups or evaluation times.ConclusionEccentric contraction training promotes functional adaptation. Moreover, both concentric and eccentric contraction training have a protective effect on the muscle in relation to a single session of maximum strength exercise.Trial registrationRBR-75scwh

Circulating Tumor Necrosis Factor Alpha May Modulate the Short-Term Detraining Induced Muscle Mass Loss Following Prolonged Resistance Training

“…The results from the current study show that systemic levels of TNFα are not significantly altered by an 8-week RT program. This is also in somewhat of agreement with the study of Alves et al (2013) whom reported that following 10 RT sessions over 3 weeks, there were no significant changes in circulating TNFα 24–96 h post the final RT session. The current study is slightly in contrast with that of Paoli et al (2015).…”

“…In a study by Townsend et al (2013) also investigating the acute response to RT, the authors showed that in resistance-trained men, circulating TNFα was significantly increased immediately post-RT compared to pre-RT. However, TNFα levels had returned to baseline within 30 min post-RT, remaining as such for a further 24 and 48 h. This is in somewhat of agreement with the study of Alves et al (2013) who demonstrated that following either eccentric or concentric RT only, there were no acute increases in TNFα post-RT (24–96 h). Furthermore, this study also showed that following 10 RT sessions over 3 weeks, there were no significant changes in circulating TNFα 24–96 h post the final RT session.…”

“…Townsend et al (2013) showed with the acute response to RT, circulating TNFα was significantly increased immediately post-RT compared to pre-RT in resistance trained men. However, TNFα levels had returned to baseline within 30 min post-RT, remaining as such for a further 24 and 48 h. Similarly, Alves et al (2013) demonstrated that following either eccentric or concentric RT only, there were no acute increases in TNFα post-RT (24–96 h). In addition, Peake et al (2006) reported following submaximal and maximal lengthening contractions, no significant changes in circulating TNFα in either acute windows of 1–3 h or 1–4 days.…”