Circulating Concentration of Chemical Elements During Exercise-Induced Muscle Damage and the Repeated Bout Effect.

The objective of the study was to evaluate the circulating levels of chemical elements after exercise-induced muscle damage (EIMD) followed by the repeated bout effect (RBE). Seven physically active subjects (26.5 ± 4.0 years) performed two sessions of EIMD (5 sets of 20 drop jumps), the second session 14 days after the first for RBE assessment. Blood collections, countermovement jump (CMJ), squat jump (SJ), and delayed-onset muscle soreness (DOMS) were performed before (Pre), after (Post), and 24, 48, and 72 h after the exercise session. Creatine kinase (CK) was detected by biochemical analysis and the concentration of chemical elements by total reflection X-ray fluorescence (TXRF). Differences between time points and sessions were assessed with two-way ANOVA and the effect size (ES). EIMD induced a reduction in the CMJ at 24 h (P < 0.05) and an increase in DOMS at 24 h (P < 0.01) and 48 h (P < 0.01), and CK at 72 h (P < 0.05). RBE alleviated all symptoms of EIMD in the second session (P > 0.05). EIMD induced a large to very large ES for Zn reduction at 24 h (- 1.37) and 72 h (- 0.93) and Br (- 0.83) at 72 h. RBE presented large to very large ES for the increase in P at 48 h (0.92); Cl at 24 h (1.04); K at 24 h (0.91), 48 h (1.10), and 72 h (0.96); Ca at 72 h (0.92); and Fe at 24 h (0.85). RBE influenced the concentration of elements associated with fatigue (K, Ca, Cl), inflammatory response, and glucose metabolism (Zn).

Ergogenic Effects of Photobiomodulation on Performance in the 30-Second Wingate Test: A Randomized, Double-Blind, Placebo-Controlled, Crossover Study.

ABSTRACT: Molina Correa, JC, Padoin, S, Varoni, PR, Demarchi, MC, Flores, LJ, Nampo, FK, and de Paula Ramos, S. Ergogenic effects of photobiomodulation on performance in the 30-second Wingate test: A randomized, double-blind, placebo-controlled, crossover study. J Strength Cond Res 36(7): 1901-1908, 2022-The purpose of this study was to evaluate the ergogenic effects of red light (630 nm) photobiomodulation on anaerobic capacity in the Wingate test. Sixteen healthy and physically active male volunteers (21.71 ± 2.49 years of age, body mass index between 18.5 and 24.9 kg/m2) participated in this randomized, double-blind, placebo-controlled, crossover study. The subjects performed 3 Wingate test sessions, with a 48-hour interval between tests. In the first session (baseline session, BS), a Wingate test was performed to evaluate the initial performance. Subjects were paired by performance in the BS and allocated through a draw to receive either the phototherapy (630 nm, 4.6 J/cm2, 6 J per point, 16 points, light-emitting diode [LED] session) or placebo intervention (PLA session) in the second test session. In the third test session, a crossover intervention was performed. The repeated-measures analysis of variance test, followed by Bonferroni post hoc test or Friedman test with Dunn's post hoc test (p < 0.05) and Cohen's d statistic were used for comparisons. The LED session with phototherapy promoted an increase in performance in peak power (p < 0.05), relative power (p < 0.05), RPMpeak (p < 0.05), and peak velocity (p < 0.05), as well as total displacement (p < 0.01) compared with PLA. The mean power (p < 0.05), relative power (p < 0.05), RPMmean (p < 0.01), and mean velocity (p < 0.01) were higher in the LED session than those of BS. We concluded that phototherapy improves performance in Wingate anaerobic exercise, possibly due to large effects on the anaerobic alactic metabolism.

Phototherapy Improves Muscle Recovery and Does Not Impair Repeated Bout Effect in Plyometric Exercise.

ABSTRACT: Padoin, S, Zeffa, AC, Molina Corrêa, JC, de Angelis, TR, Moreira, TB, Barazetti, LK, and de Paula Ramos, S. Phototherapy improves muscle recovery and does not impair repeated bout effect in plyometric exercise. J Strength Cond Res 36(12): 3301-3310, 2022-The effects of photobiomodulation with red (630 nm) and near-infrared (940 nm) light wavelengths were investigated on the inhibition of exercise-induced muscle damage (EIMD) and adaptation to the repeated bout effect (RBE). Twenty-eight healthy men were randomized to receive light-emitting diode therapy (LEDT) at 630 nm (4.6 J·cm -2 , 97 J energy), LEDT at 940 nm (4.6 J·cm -2 , 114 J), or placebo. After LEDT or placebo treatment, subjects performed 100 drop-jumps (5 sets of 20 repetitions). Creatine kinase, delayed-onset muscle soreness (DOMS), countermovement jump (CMJ), and squat jump (SJ) were assessed before, immediately after, and 24, 48, and 72 hours after the bout. After 14 days, the subjects were submitted to the same plyometric exercise, without LEDT, and were evaluated again. Creatine kinase levels increased significantly 72 hours after the first bout in the placebo group in relation to the LEDT 940-nm group ( P < 0.01). The LEDT 630-nm group showed a significant increase in SJ at 24 hours ( P < 0.05), whereas, at 48 hours, the LEDT 940 nm showed a significant increase compared with the placebo group ( P < 0.05). The 2-way analysis of variance revealed an effect for treatment in the SJ ( F = 7.12; P = 0.001). No differences were found between groups for DOMS and CMJ after the first bout. After the second bout of exercise, there was no effect of treatment. The results suggest that treatment with LEDT 630 nm and LEDT 940 nm before eccentric exercise attenuates EIMD without impairing RBE.

Effects of Futsal Demands on Serum and Salivary Levels of Trace Elements and Minerals Detected by Total Reflection X-Ray Fluorescence.

The aim of this study was to monitor the circulating and salivary ion concentrations by total reflection X-ray fluorescence (TXRF) in futsal players submitted to the futsal-specific intermittent shuttle protocol (FISP). TXRF may allow identification of changes in ion concentrations induced by physical efforts. Saliva and blood samples of 13 male futsal players were collected before (Pre) and after (Post) the FISP. Salivary and plasma ion levels were detected by TXRF, and differences from Pre to Post (paired t test or Wilcoxon test) and correlations between both biological fluids were determined (P < 0.05). All saliva samples presented phosphorus (P), sulfur (S), chlorine (Cl), potassium (K), calcium (Ca), iron (Fe), zinc (Zn), bromine (Br), and rubidium (Rb). S, Cl, Ca, Fe, Cu, Zn, Br, and Rb were detected in all blood samples. K, Cu, Br, and Rb presented reduced secretion rate from Pre to Post samples (P < 0.05). The salivary concentrations of K (r = - 0.53) and Zn (r = 0.54) were correlated with plasmatic concentrations. After FISP, salivary secretion of S (r = - 0.76), Cl (r = - 0.64), P (r = - 0.67), Mn (r = - 0.74), and Zn (r = 0.69) were correlated with plasma levels. We concluded that TXRF may be used to monitor salivary (P, S, Cl, K, Ca, Fe, Zn, Br, and Rb) and circulating (S, Cl, Ca, Fe, Cu, Zn, Br, and Rb) levels of several elements in futsal athletes. However, an acute bout of futsal-specific physical effort did not significantly imbalance ion concentrations in saliva or plasma.