Photobiomodulation does not improve anaerobic performance in well-trained cyclists.

To determine if photobiomodulation (PBM) has ergogenic effects on the anaerobic performance of well-trained cyclists. Fifteen healthy male road or mountain bike cyclists participated in this randomized, double-blinded, placebo-controlled, crossover study. Athletes were randomly assigned to receive photobiomodulation (630 nm, 4.6 J/cm2, 6 J per point, 16 points, PBM session) or placebo intervention (PLA session) in the first session. The athletes then performed a 30-s Wingate test to determine mean and peak average power, relative power, mean and peak velocity, mean and peak RPM, fatigue index, total distance, time to peak power, explosive strength, and power drop. After 48 h, athletes returned to the laboratory for the crossover intervention. The repeated-measures ANOVA 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. Performance in the Wingate test was not significantly different (p > 0.05) between PBM and PLA sessions for any variable. Only a small effect size was detected for time to peak power (-0.40; 1.11 to 0.31) and explosive strength (0.38; -0.34 to 1.09). We conclude that irradiation with red light, under a low energy density, does not promote ergogenic effects on the anaerobic performance of cycling athletes.

Importância da ginástica laboral na flexibilidade de coluna em servidores do Hospital Universitário / Importance of occupational gymnastics in spine flexibility in workers at the university hospital

Introdução: os cuidados com os trabalhadores é uma importante questão de saúde pública. Objetivo: avaliar os efeitos da ginástica laboral (GL) na flexibilidade da coluna cervical e lombar de servidores do hospital universitário. Materiais e Métodos: trata-se de um estudo experimental. Participaram do estudo, 50 colaboradores distribuídos em dois grupos: Controle (CTL, n=25) e Experimental (EXP, n=25). O grupo CLT não participou das aulas de GL e o grupo EXP realizou 16 sessões de GL, quatro vezes por semana, por quatro semanas. A flexibilidade da coluna cervical e lombar dos participantes foi realizada em dois momentos, antes de iniciarem o programa de GL e após 16 sessões. Resultados: foi verificado que a prática de GL resultou em um aumento da flexibilidade cervical. Em relação à coluna lombar, o período de intervenção não impediu a redução da flexibilidade, no entanto, essa redução foi 50% menor no grupo EXP quando comparado ao grupo CTL. Conclusão: o programa de GL é uma estratégia de intervenção fundamental para a saúde do trabalhador, visto que a flexibilidade é um importante componente da atividade física relacionada à saúde.

Introduction: care of workers is an important public health issue. Objective: to evaluate the effects of occupational gymnastics (OG) on the flexibility of the cervical and lumbar spine of employees at the university hospital. Materials and Methods: this is an experimental study. A total of 50 employees participated in the study, divided into two groups: Control (CTL, n = 25) and Experimental (EXP, n = 25). The CLT group did not participate in the OG classes and the EXP group had 16 OG sessions, which took place four times a week, for four weeks. The flexibility of the cervical and lumbar spine of the participants was assessed in two moments, before starting the OG program and after 16 sessions. Results: it was observed that the practice of OG resulted in an increase in cervical flexibility. Regarding the lumbar spine, the intervention period did not prevent the reduction in flexibility; however, this reduction was 50% lower in the EXP group when compared to the CTL group. Conclusion: the OG program is a fundamental intervention strategy for workers' health, since flexibility is an important component of physical activity related to health.

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).

The use of BCAA to decrease delayed-onset muscle soreness after a single bout of exercise: a systematic review and meta-analysis.

Branched-chain amino acids (BCAA) are used as a recovery method after exercise-induced muscle damage (EIMD). Although data suggest that BCAA may alleviate the delayed-onset muscle soreness (DOMS) evoked by EIMD, there is no consensus about the most effective supplementation protocol. To investigate the effects of BCAA on DOMS after a single exercise session that caused EIMD, a systematic review and meta-analysis were conducted on the effectiveness of BCAA supplementation to reduce DOMS symptoms in healthy subjects after a single session of EIMD. Randomized clinical trials (RCT) were searched in Medline, Cochrane Library, Science Direct, SciELO, LILACS, SciVerse Scopus, Springer Link journals, Wiley Online Library, and Scholar Google, until May 2021. Ten RCTs were included in the systematic review and nine in the meta-analysis. Seven studies demonstrated that BCAA reduced DOMS after 24 to 72 h. BCAA doses of up to 255 mg/kg/day, or in trained subjects, for mild to moderate EIMD, could blunt DOMS symptoms. However, high variability between studies due to training status, different doses, time of treatment, and severity of EIMD do not allow us to conclude whether BCAA supplementation is efficient in untrained subjects, applied acutely or during a period of pre to post days of EIMD, and at higher doses (> 255 mg/kg/day). The overall effects of BCAA on DOMS after a single session of exercise were considered useful for improving muscle recovery by reducing DOMS in trained subjects, at low doses, in mild to moderate EIMD, and should not be administered only after the EIMD protocol.