Effect of hypnotic suggestion on knee extensor neuromuscular properties in resting and fatigued states

The aim of this study was to investigate whether hypnotic suggestions can alter knee extensor neuromuscular function at rest and during exercise. Thirteen healthy volunteers (8 men and 5 women, 27 ± 3 years old) took part in this counterbalanced, crossover study including two experimental (hypnosis and control) sessions. Knee extensor neuromuscular function was tested before and after hypnosis suggestion by using a combination of voluntary contraction, transcutaneous femoral nerve electrical stimulation and transcranial magnetic stimulation (TMS). A fatiguing exercise (sustained submaximal contraction at 20% maximal voluntary contraction (MVC) force) was also performed to evaluate the potential influence of hypnosis on the extent and origin of neuromuscular adjustments. Hypnosis did not (p>0.05) alter MVC force or knee extensor neural properties. Corticospinal excitability, assessed with the amplitude of knee extensor motor evoked potentials, was also unchanged (p>0.05), as was the level of intracortical inhibition assessed with paired pulse TMS (short-interval intracortical inhibition, SICI). Time to task failure (~300 s) was not different (p>0.05) between the two sessions; accordingly, hypnosis did not influence neuromuscular adjustments measured during exercise and at task failure (p>0.05). Hypnotic suggestions did not alter neuromuscular properties of the knee extensor muscles under resting condition or during/after exercise, suggesting that hypnosis-induced improvement in exercise performance and enhanced corticospinal excitability might be limited to highly susceptible participants

Recovery following rugby union matches: Effects of cold water immersion on markers of fatigue and damage

© 2019, Canadian Science Publishing. All rights reserved. We investigated the effect of postmatch cold-water immersion (CWI) on markers of muscle damage, neuromuscular fatigue, and perceptual responses within 72 h after a rugby match. Twenty-two professional male rugby players were randomized into CWI (10 °C/10 min; n = 11) or control (CON: 30 min seated; n = 11) groups. Activity profile from Global Positioning Satellite systems and postmatch rating of perceived exertion were measured to determined match load. Biochemical (tumor necrosis factor alpha (TNF-α), interleukin-6), neuromuscular performance (squat (SJ) and countermovement jumps (CMJ), peak power output (PPO), rate of force development (RFD), stiffness, 10-and 30-m sprint time, and perceptual markers (soreness, perceived recovery) were obtained before and immediately after the match, and then at 30 min, 24 h, 48 h, and 72 h after the match. Magnitude-based inference and Cohen’s effect size (ES) were used to analyze change over time and between groups. Thus, the higher/beneficial, similar/trivial, or lower/harmful differences were evaluated as follows: 99%, almost certainly. Changes were unclear for the match loads, sprint times, and perceptual markers between groups. Higher %ΔSJ at 24 h (very likely (ES = 0.75)) and in %ΔPPO_SJ at 48 h (likely (ES = 0.51)) were observed in CWI than in CON. Values in %ΔRDF_CMJ were higher immediately after (likely (ES = 0.83)), 30 min after (very likely (ES = 0.97)), and 24 h after the match (likely (ES = 0.93)) in CWI than in CON. Furthermore, %Δlog TNF-α were lower in the CWI group than in the CON group immediately after (almost certainly (ES = −0.76)), 24 h after (very likely (ES = −1.09)), and 72 h after the match (likely (ES = −0.51)), and in Δstiffness_SJ at 30 min after (likely (ES = −0.67)) and 48 h after the match (very likely (ES = −0.97)). Also, different within-groups effects throughout postmatch were reported. Implementing postmatch CWI-based strategies improved the recovery of markers of inflammation and fatigue in rugby players, despite no change in markers of speed or perceptual recovery

Post-match recovery in soccer with far-infrared emitting ceramic material or cold-water immersion

We investigated the effects of two common recovery methods; far-infrared emitting ceramic materials (Bioceramic) or cold-water immersion on muscular function and damage after a soccer match. Twenty-five university-level soccer players were randomized into Bioceramic (BIO; n = 8), Cold-water immersion (CWI; n = 9), or Control (CON; n = 8) groups. Heart rate [HR], rating of perceived exertion [RPE], and activity profile through Global Positioning Satellite Systems were measured during the match. Biochemical (thiobarbituric acid reactive species [TBARS], superoxide dismutase [SOD], creatine kinase [CK], lactate dehydrogenase [LDH]), neuromuscular (countermovement [CMJ] and squat jump [SJ], sprints [20-m]), and perceptual markers (delayed-onset muscle soreness [DOMS], and the perceived recovery scale [PRS]) were assessed at pre, post, 24 h, and 48 h postmatch. One-way ANOVA was used to compare anthropometric and match performance data. A two-way ANOVA with post-hoc tests compared the timeline of recovery measures. No significant differences existed between groups for anthropometric or match load measures (P > 0.05). Significant post-match increases were observed in SOD, and decreases in TBARS in all groups (p 0.05). Significant increases in CK, LDH, quadriceps and hamstring DOMS (p 0.05). Despite the expected post-match muscle damage and impaired performance, neither Bioceramic nor CWI interventions improved post-match recovery

Assessment of anaerobic power of swimmers: the correlation of laboratory tests on an arm ergometer with field tests in a swimming fool

The aim of this study was to verify the correlation between the Wingate arm crank test outputs (peak power, mean power, and fatigue index), obtained on a specific ergometer, and the performance in crawl stroke swim sprints of 14, 25, 50, and 400 m. The experiment was conducted with 9 healthy male volunteers (18.1 +/- 2.2 years of age; 172 +/- 0.04 cm; 67.7 +/- 5.92 kg and 15.7 +/- 4.57% body fat). on determined days, all individuals were submitted to the Wingate arm crank test and crawl freestyle sprints of 14, 25, 50, and 400 m as they were timed with a stopwatch. The peak power, the mean power, and the fatigue index, which were obtained during the Wingate arm crank test, were not significantly correlated with the maximum swim velocities during the crawl free-style tests of 14 (r = 0.40; r = 0.64; r = 0.11), 25 (r = 0.28; r = 0.39; r = -0.27), 50 (r = 0.03; r = 0.09; r = -0.31), and 400 (r = -0.52; r = -0.37; r = -0.65) m respectively. Thus, it is possible to conclude that the Wingate arm crank test is not suitable to assess the anaerobic power of swimmers under the described experimental conditions

Effects of Far‐Infrared Emitting Ceramic Material Clothing on Recovery After Maximal Eccentric Exercise

Abstract The purpose of this study was to determine whether Far-Infrared Emitting Ceramic Materials worn as Bioceramic pants would improve neuromuscular performance, biochemical and perceptual markers in healthy individuals after maximal eccentric exercise. Twenty-two moderately active men were randomized into Bioceramic (n = 11) or Placebo (n = 11) groups. To induce muscle damage, three sets of 30 maximal isokinetic eccentric contractions of the quadriceps were performed at 60°·s-1. Participants wore the bioceramic or placebo pants for 2 hours immediately following the protocol, and then again for 2 hours prior to each subsequent testing session at 24, 48 and 72 hours post. Plasma creatine kinase and lactate dehydrogenase activity, delayed-onset muscle soreness, perceived recovery status, and maximal voluntary contraction were measured pre-exercise and 2, 24, 48, and 72 hours post-exercise. Eccentric exercise induced muscle damage as evident in significant increases in delayed-onset muscle soreness at 24 - 72 hours (p &lt; 0.05) and creatine kinase between Pre to 2, 24, 48 and 72 hours (p &lt; 0.05). Despite the increased delayed-onset muscle soreness and creatine kinase values, no effect of Bioceramic was evident (p &gt; 0.05). Furthermore, decreases in maximal voluntary contraction between Pre and immediately, 2, 24, 48 and 72 hours post (p &lt; 0.05) were reported. However, the standardized difference was moderate lower for lactate dehydrogenase at 24 h (ES = 0.50), but higher at 48 h (ES = -0.58) in the Bioceramic compared to the Placebo group. Despite inducing muscle damage, the daily use of Far-Infrared Emitting Ceramic Materials clothing over 72 hours did not facilitate recovery after maximal eccentric exercise.</jats:p