Effects of Photobiomodulation/Laser Therapy Combined With Resistance Training on Quadriceps Hypertrophy and Strength, and Postural Balance in Older Women: A Randomized, Triple-Blinded, Placebo-Controlled Study.

BACKGROUND AND PURPOSE: Physical and therapeutic strategies to maintain and rehabilitate skeletal muscle mass, strength, and postural balance are clinically relevant to improve the health, well-being, and quality of life of older adults. The purpose of this study was to investigate the effects of photobiomodulation (PBM)/laser therapy combined with a resistance training (RT) program on quadriceps hypertrophy and strength, and postural balance in older women. METHODS: In a randomized, triple-blinded, placebo-controlled design, twenty-two older women (age 66.6 ± 5.2 years) were engaged in a supervised 10-wk RT program (2 times per week) involving unilateral leg extension exercise, in which each leg of the same participant was randomly assigned to receive active (λ = 808 nm, optical output = 100 mW, total energy = 42 J) or placebo laser PBM immediately before the RT sessions. Maximal dynamic strength by unilateral knee extension 1-repetition maximum (1RM), muscle hypertrophy by vastus lateralis muscle thickness, and postural balance by one-legged stance test on a force platform were assessed before and after the training program. RESULTS: Significance statistical analysis revealed a similar improvement (time P = .003) from pre- to posttraining for muscle hypertrophy and strength, and postural balance between active and placebo laser conditions. However, clinical interpretation for muscle hypertrophy showed a moderate effect (effect size [ES] = 0.58) for the active laser and a small effect (ES = 0.38) for the placebo laser. Clinical difference was not noticed between conditions for other analyzed variables. CONCLUSIONS: These findings indicate that RT alone can be clinically important for counteracting the deleterious effects of aging on muscle size, strength, and balance, and that applying laser PBM therapy before the RT sessions may further improve gains in muscle hypertrophy.

Analysis of postural balance in children who practice and those who do not practice sports activities / Análisis del equilibrio postural en niños que practican y no practican atividades deportivas / Análise do equilíbrio postural em crianças praticantes e não praticantes de atividades esportivas

ABSTRACT Introduction: Postural balance is essential for activities of daily living and sports performance in all life phases, but it remains unknown whether the regular practice of sports activities can improve postural balance in children. Objective: To evaluate postural balance in children who practice and those who do not practice regular sports activities. Methods: The sample consisted of 60 children (7-13 years of age) divided into two groups: participants in sports activities (n = 30) and non-participants in sports activities (n = 30). The level of physical activity was assessed by applying the Physical Activity Questionnaire for Children (PAQ-C) and static postural balance was assessed on the BIOMEC400-412 strength platform in bipedal and unipedal support. Results: No significant difference was observed between the groups in age, height or body mass index (p > 0.05). However, the groups showed a significant difference (p < 0.001) in the level of physical activity. The practicing sports group was characterized as active and the non-practicing group as sedentary. The practicing sports group had better postural balance in both bipedal and unipedal support compared to the non-practicing group (p < 0.05). Conclusion: The practice of regular sports activities improves postural balance in children from 7 to 13 years of age. Level of evidence II; Diagnostic study - Investigating a diagnostic test.

RESUMEN Introducción: El equilibrio postural es esencial para las actividades de la vida diaria y el rendimiento deportivo en todas las edades, pero se desconoce si las actividades deportivas regulares pueden mejorar el equilibrio postural en los niños.. Objetivo: Evaluar el equilibrio postural en niños que practican y no practican actividades deportivas habituales. Métodos: La muestra estuvo formada por 60 niños (7 a 13 años) divididos en dos grupos: practicantes de actividades deportivas (n = 30) y no practicantes de actividades deportivas (n = 30). El nivel de actividad física se evaluó mediante la aplicación del Cuestionario de Actividad Física para Niños (PAQ-C) y el equilibrio postural en condición estática se evaluó en la plataforma de fuerza BIOMEC400-412 en soporte bípedo y unipodal. Resultados: No se observó diferencia significativa entre los grupos en cuanto a edad, talla e índice de masa corporal (p > 0.05). Sin embargo, los grupos mostraron una diferencia significativa (p < 0,001) con respecto al nivel de actividad física, el grupo que practica deporte se caracterizó como activo y el grupo no practicante como sedentario. El grupo que practica deporte presentó mejor equilibrio postural tanto en apoyo bípedo como unipodal, cuando se compara con el grupo no practicante (p < 0,05). Conclusión: La práctica de actividad deportiva regular mejora el equilibrio postural en niños de 7 a 13 años. Nivel de evidencia II; Estudio de diagnóstico - Investigación de un examen para diagnóstico.

RESUMO Introdução: O equilíbrio postural é fundamental para as atividades da vida diária e desempenho esportivo em todas as fases da vida, mas permanece desconhecido se a prática de atividade esportiva regular pode melhorar o equilíbrio postural em crianças. Objetivo: Avaliar o equilíbrio postural em crianças praticantes e não praticantes de atividade esportiva regular. Métodos: A amostra foi composta por 60 crianças (idade: 7-13 anos), divididas em dois grupos: praticantes de atividades esportivas (n = 30) e não praticantes de atividades esportivas (n = 30). O nível de atividade física foi avaliado com a aplicação do questionário Physical Activity Questionnaire for Children (PAQ-C) e o equilíbrio postural em condição estática foi avaliado sobre a plataforma de força BIOMEC400-412 em apoio bipodal e unipodal. Resultados: Nenhuma diferença significativa foi observada entre os grupos quanto a idade, estatura e índice de massa corporal (p > 0,05). Entretanto, os grupos apresentaram diferença significativa (p < 0,001) quanto ao nível de atividade física; o grupo praticante de atividade esportiva foi caracterizado como ativo e o grupo não praticante como sedentário. O grupo praticante de atividade esportiva apresentou melhor equilíbrio postural tanto em apoio bipodal como unipodal, quando comparado ao grupo não praticante (p < 0,05). Conclusão: A prática de atividade esportiva regular melhora o equilíbrio postural em crianças de 7 a 13 anos de idade. Nível de evidência II; Estudo diagnóstico - Investigação de um exame para diagnóstico.

Photobiomodulation Therapy at 808 nm Does Not Improve Biceps Brachii Performance to Exhaustion and Delayed-Onset Muscle Soreness in Young Adult Women: A Randomized, Controlled, Crossover Trial.

OBJECTIVE: This study aims to investigate the effects of laser photobiomodulation (PBM) at 808 nm on biceps brachii performance to exhaustion, rating of perceived exertion (RPE), and delayed onset muscle soreness (DOMS) in untrained young women. METHODS: Thirteen young women (20.1 ± 2.9 years) participated in a crossover study in which they received, in a counterbalanced manner, active and placebo laser PBM on two occasions (T1 and T2), separated by a 7-day washout period. During T1 and T2, participants received active (100 mW output power, irradiance of 35.7 W cm-2, and total energy of 28 J/arm) or placebo laser irradiation on the biceps brachii muscle at 20 min before the repetitions-to-failure test [six sets at 60% of one-repetition maximum (1RM) until failure] for elbow flexion exercise. The number of repetitions performed and RPE over the six sets, as well as DOMS from basal up to 72 h after the repetitions-to-failure test, were recorded. RESULTS: There was a significant (time, p < 0.05) reduction in the number of repetitions performed and an increase in RPE over six sets, with no statistical differences between placebo and active laser conditions (treatment × time, p > 0.05). DOMS increased at 24 h postexercise and progressively returned to baseline after 72 h in both conditions (time, p < 0.05; treatment × time, p > 0.05). CONCLUSION: Our results indicate that acute laser PBM at 808 nm does not improve biceps brachii performance to exhaustion, RPE, and DOMS in untrained women.

Effects of Citrulline Malate Supplementation on Aerobic and Muscular Endurance in Young Adults Men / Efeitos da Suplementação de Citrulina Malato sobre a Resistência Aeróbica e Muscular em Homens Adultos Jovens

The aim of this study was to evaluate the effects of citrulline malate (CIT) supplementation on aerobic and muscular endurance in young adult males. Eighteen young adult men (age: 21.5 ± 2.7 years) were randomized into two groups (Citrulline malate - CIT and Placebo - PLA; N = 9/ group ) and received the respective supplements for 7 days. The CIT group was supplemented with 6 g CIT + 6 g dextrose (total: 12 g), while the PLA group received the same amount (12 g) of dextrose. At the pre- and post-supplementation, the following variables were analyzed: aerobic (maximal treadmill test, Tmax) and muscle (repetitions maximum test, Rmax) endurance tests, as well as mean and maximum heart rate (HR) in Tmax and ratings of perceived exertion (PSE) in Rmax. No significant (P > 0.05) differences were found between CIT and PLA groups in time until exhaustion in Tmax, total repetitions in Rmax, maximal HR and PSE from pre- to post-supplementation. The mean HR was statistically lower (P < 0.05) in the CIT group compared to the PLA in the Tmax. In conclusion, supplementation of CIT (6 g / day) does not improve aerobic and muscular endurance, as well as maximal HR or PSE in healthy young adults, despite reducing the mean HR during the maximal incremental test. (AU)

O objetivo deste estudo foi avaliar os efeitos da suplementação de citrulina malato (CIT) sobre a resistência aeróbica e muscular em homens adultos jovens. Em um desenho experimental randomizado, duplo-cego e controlado com placebo, dezoito homens adultos jovens (idade: 21,5 ± 2,7 anos) foram randomizados em dois grupos (Citrulina malato ­ CIT e Placebo ­ PLA; N = 9/grupo) e receberam os respectivos suplementos por um período de 7 dias. O grupo CIT foi suplementado com 6 g de CIT + 6 g de dextrose (total: 12 g), enquanto o grupo PLA recebeu a mesma quantidade (12 g) de dextrose. Nos momentos pré e pós suplementação as seguintes variáveis foram analisadas: resistência aeróbia (teste incremental máximo em esteira rolante, Tmáx) e muscular (teste de repetições máximas, Rmáx), bem como a frequência cardíaca (FC) média e máxima no Tmáx e a análise da percepção subjetiva de esforço (PSE) no Rmáx. Nenhuma diferença significante (P > 0,05) foi encontrada entre os grupos CIT e PLA no tempo até a exaustão no Tmáx, total de repetições no Rmáx, FC máxima e PSE do momento pré para o pós suplementação. A FC média foi estatisticamente (P < 0,05) menor no grupo CIT comparado ao PLA no Tmáx. Em conclusão, a suplementação de CIT (6 g/dia) não melhora a resistência aeróbica e muscular, bem como a FC máxima ou PSE em adultos jovens saudáveis, apesar de reduzir a FC média durante o teste incremental máximo. (AU)

Branched-chain amino acids do not improve muscle recovery from resistance exercise in untrained young adults.

The purpose of this study was to investigate the effects of BCAA supplementation on muscle recovery from resistance exercise (RE) in untrained young adults. Twenty-four young adults (24.0 ± 4.3 years old) were assigned to 1 of 2 groups (n = 12 per group): a placebo-supplement group or a BCAA-supplement group. The groups were supplemented for a period of 5 days. On day 1 and 3, both groups underwent a RE session involving two lower body exercises (hack squat and leg press) and then were evaluated for muscle recovery on the 3 subsequent moments after the RE session [30 min (day 3), 24 h (day 4), and 48 h (day 5)]. The following indicators of muscle recovery were assessed: number of repetitions, rating of perceived exertion in the last RE session, muscle soreness and countermovement jump (CMJ) during recovery period (30 min, 24 h, and 48 h after RE session). Number of repetitions remained unchanged over time (time, P > 0.05), while the rating of perceived exertion increased (time, P < 0.05) over 3 sets, with no difference between groups (group × time, P > 0.05). Muscle soreness increased (time, P < 0.05) and jumping weight decreased (time, P < 0.05) at 30 min post-exercise and then progressively returned to baseline at 24 and 48 h post-exercise, with no difference between groups (group × time, P > 0.05). The results indicate that BCAA supplementation does not improve muscle recovery from RE in untrained young adults.

Effects of beta-alanine supplementation on muscle function during recovery from resistance exercise in young adults.

ß-Alanine supplementation has been shown to increase muscle carnosine levels and exercise performance. However, its effects on muscle recovery from resistance exercise (RE) remains unknown. The purpose of this study was to investigate the effects of ß-alanine supplementation on muscle function during recovery from a single session of high-intensity RE. Twenty-four untrained young adults (22.1 ± 4.6 years old) were assigned to one of two groups (N = 12 per group): a placebo-supplement group (4.8 g/day) or an ß-alanine-supplement group (4.8 g/day). The groups completed a single session of high-intensity RE after 28 days of supplementation and were then evaluated for muscle function on the three subsequent days (at 24, 48, and 72 h postexercise) to assess the time course of muscle recovery. The following indicators of muscle recovery were assessed: number of repetitions until failure, rating of perceived exertion, muscle soreness, and blood levels of creatine kinase (CK). Number of repetitions until failure increased from 24 to 48 h and 72 h of recovery (time P < 0.01), with no difference between groups. There was a significant increase in the rating of perceived exertion among the sets during the RE session (time P < 0.01), with no difference between the groups. No difference was observed over time and between groups in rating of perceived exertion in the functional tests during recovery period. Blood CK levels and muscle soreness increased at 24 h postexercise and then progressively declined at 48 and 72 h postexercise, respectively (time P < 0.05), with no difference between groups. In conclusion, our data indicate that ß-alanine supplementation does not improve muscle recovery following a high-intensity RE session in untrained young adults.

l-Arginine supplementation does not improve muscle function during recovery from resistance exercise.

The purpose of this study was to investigate the effects of l-arginine supplementation on muscle recovery after a single session of high-intensity resistance exercise (RE). Twenty healthy young adult participants (22.8 ± 3.4 years old) were assigned to 1 of 2 groups (N = 10 per group): a placebo-supplement group or an l-arginine-supplement group. The groups completed a session of high-intensity RE (0 h) and 3 subsequent fatigue test sessions (at 24, 48, and 72 h postexercise) to assess the time course of muscle recovery. During the test sessions, we assessed the following dependent variables: number of maximum repetitions, electromyographic signal (i.e., root mean square (RMS) and median frequency (MF) slope), muscle soreness, perceived exertion, blood levels of creatine kinase (CK) and lactate, and testosterone:cortisol ratio. Number of maximum repetitions increased at 48 and 72 h postexercise in both groups (time, P < 0.05). CK levels and muscle soreness increased at 24 h postexercise and then progressively returned to baseline at 72 h post exercise in both groups (time, P < 0.05). Lactate levels increased immediately postexercise but were reduced at 24 h postexercise in both groups (time, P < 0.05). Testosterone:cortisol ratio, RMS, and MF slope remained unchanged during the recovery period in both groups (time, P > 0.05). No significant (P > 0.05) group × time interaction was found for all dependent variables during the recovery period. In conclusion, our data indicate that l-arginine supplementation does not improve muscle recovery following a high-intensity RE session in young adults.

Efeitos da Suplementação de Leucina Associada ao Treinamento Resistido Sobre a Força Muscular em Sujeitos Jovens / Effects of Leucine Supplementation Associated with Resistance Training on Muscle Strength in Young Subjects

A proposta do presente estudo foi avaliar os efeitos da suplementação de leucina associada ao treinamento resistido (TR) de alta intensidade sobre a força muscular em sujeitos jovens não treinados. Para tanto, 24 indivíduos jovens não treinados, de ambos os sexos, foram divididos em dois grupos (N = 12/grupo): Leucina (4g de leucina + 8g dextrose) e Placebo (12g dextrose). Ambos os grupos foram submetidos a um programa de TR de alta intensidade (3 séries de 12 repetições máximas; 2x/semana) com duração de 6 semanas, e consumiram seus respectivos suplementos imediatamente após cada sessão de treino. As sessões de treino consistiram na realização dos exercícios de leg press e cadeira extensora, a fim de maximizar o recrutamento do músculo quadríceps. Ambos os grupos foram submetidos ao teste de uma repetição máxima (1RM) nos exercícios de leg press e cadeira extensora, nos momentos pré e pós-treinamento. Ao término do treinamento, houve um significante (P < 0,05) aumento do 1RM em ambos os exercícios, mas nenhuma diferença foi observada entre os grupos. Além disso, a progressão da carga de treino foi similar (P > 0,05) entre os grupos, após 4 e 6 semanas de treinamento. Estes resultados indicam que a suplementação de uma baixa dose semanal de leucina (4g/dia; 2x/semana) associada ao TR em curto prazo não promove efeitos adicionais sobre a força muscular em indivíduos jovens não treinados. (AU)

The purpose of the study herein was to examine the leucine supplementation effects associated with high-intensity resistance training (RT) on muscle strength in young untrained subjects. Twenty-four young untrained subjects fromboth sexes were divided into two groups (N = 12/ group): Leucine (4g leucine + 8g dextrose) and Placebo (12g dextrose). Both groups underwent a 6-wk high-intensity RT program (3 sets of 12 maximal repetitions; 2x/week), and consumed their respective supplements immediately after each training session. The training sessions consisted of performing leg press and knee extension exercises, in order to maximize the recruitment of the quadriceps muscle. Both groups performed the one-repetition maximum (1RM) test in the leg press and extensor chair exercises at pre- and post-training. After RT program, there was a significant (P < 0.05) increased 1RM in both exercises, but no difference was observed between the groups. In addition, the training load progression was similar (P > 0.05) between the groups after 4 and 6 weeks of training. These results indicate that low dose supplementation of leucine (4g/day; 2x/week) associated with a short-term RT program does not promote additional effects on muscle strength in untrained young subjects. (AU)

Efeitos da Caminhada em Ritmo Prescrito e Autosselecionado sobre a Capacidade Funcional de Mulheres Idosas / Walking Effects at a Prescribed and Self-Selected Rhythm on the Elderly Women Functional Capacity

A proposta do presente estudo foi comparar os possíveis efeitos de um programa de caminhada em ritmo prescrito e autosselecionado sobre os componentes neuromotores (agilidade, força e equilíbrio) e cardiorrespiratórios em mulheres idosas. Para tanto, 26 mulheres idosas saudáveis (69,3 2,4 anos) foram aleatoriamente divididas em três grupos: Prescrito (PRE, N = 8), Autosselecionado (SEL, N = 9) e Controle (CON, N = 9). Os grupos PRE e SEL foram submetidos a um programa de atividade aeróbica de caminhada (3 vezes por semana), com duração de cinco semanas. A única diferença entre os grupos foi a intensidade de exercício físico. O grupo PRE realizou a caminhada em intensidade referente aos valores 12-13 da escala de Borg, enquanto o grupo SEL realizou a caminhada em ritmo autosselecionado, sem qualquer intervenção dos pesquisadores. O grupo CON permaneceu sem qualquer tipo de atividade durante todo o período de estudo. Todos os grupos foram submetidos a uma bateria de testes de aptidão física (agilidade, força de membros inferiores, equilíbrio e capacidade aeróbica) nos momentos pré e póstreinamento. O programa de caminhada em ritmo prescrito (PRE) promoveu efeitos adicionais sobre os componentes neuromotores (agilidade, força, equilíbrio) e cardiorrespiratórios, enquanto nenhum benefício foi observado no grupo que realizou a caminha em ritmo autosselecionado (SEL). Estes resultados demonstram que a autosseleção do ritmo de caminhada pode subestimar a intensidade necessária para promover efeitos benéficos sobre a capacidade funcional e cardiorrespiratória de mulheres idosas, indicando que a prescrição da intensidade de exercício é fundamental para esta população.(AU)

The purpose of the present study was to compare the possible effects of a prescribed and self-selected walking program on neuromotor (agility, strength, and balance) and cardiorespiratory components in elderly women. Twenty-six healthy elderly women (69.3 ± 2.4 years) were randomly divided into three groups: Prescribed (PRE, N = 8), Self-selected (SEL, N = 9) and Control (CON, N = 9). The PRE and SEL groups underwent anaerobic walking activity program (3 times a week), for 5 weeks. The only difference between the groups was the exercise intensity; The PRE group performed the walking in moderate intensity (12-13 on Borg scale), while the SEL group performed the walking in a self-selected intensity, without any researchers' intervention. The CON group remained without any type of activity throughout the study period. All groups underwent a physical fitness tests battery (agility, lower limb strength, balance and aerobic capacity) at pre and post-training. The walking in prescribed intensity (PRE) promoted additional effects on neuromotor (agility, strength, balance) and cardiorespiratory components, while no benefit effect was observed in the self-selected group (SEL). These results demonstrate that walking self-selection rhythm may underestimate the intensity required to promote beneficial effects on the elderly women's functional and cardiorespiratory capacity, indicating that exercise intensity prescription is fundamental for this population.(AU)