Effects of photobiomodulation therapy in aerobic endurance training and detraining in humans: Protocol for a randomized placebo-controlled trial.

INTRODUCTION: Over the last 10 years, it has been demonstrated that photobiomodulation therapy (PBMT), also known as phototherapy, using low-level laser therapy (LLLT) and/or light-emitting diode therapy (LEDT) has ergogenic effects, improving athletic performance and also accelerating post-exercise recovery. However, many aspects related to these effects and its clinical applicability remain unknown. Therefore, the aim of this project is to evaluate the ergogenic effects of PBMT in detraining after an aerobic endurance training protocol. METHODS AND ANALYZES: A randomized, triple-blind, placebo-controlled clinical trial will be carried out. Healthy male volunteers will be randomly distributed into 4 experimental groups: PBMT before and after training sessions + PBMT during detraining, PBMT before and after training sessions + placebo during detraining, placebo before and after training sessions + PBMT during detraining, and placebo before and after training sessions + placebo during detraining. The aerobic endurance training sessions will be carried out using motorized treadmills during 12 weeks, and the detraining period will consist in the next 4 weeks after that. It will be analyzed the time until exhaustion, maximal oxygen uptake (VO2max), and fat percentage of volunteers. DISCUSSION: Despite the increasing body of evidence for the use of PBMT as an ergogenic agent, several aspects remain unknown. The findings of this study will contribute to the advance of knowledge in this field regarding clinical applications. ETHICS AND DISSEMINATION: This study was approved by the Research Ethics Committee of Nove de Julho University. The results from this study will be further disseminated through scientific publications in international peer-reviewed journals and presentations at national and international scientific meetings. TRIAL REGISTRATION NUMBER: NCT03879226.

[The association between body fat distribution and calcaneal bone mineral density in children and adolescents aged 6-16 years in Beijing].

Objective: To understand the association between body fat distribution and calcaneal bone mineral density (BMD) in children and adolescents aged 6-16 years in Beijing. Methods: Children and adolescents were selected in 30 schools (8 primary schools, 21 middle schools and one 12-year education school) from Dongcheng, Tongzhou, Fangshan and Miyun districts of Beijing by using a stratified cluster sampling method from November 2017 to January 2018. A total of 15 030 students in grade 1 to 4 of primary school, grade 1 of junior and senior middle school were enrolled after excluding subjects who were not able to participate into this study due to trauma or other uncomfortable physical conditions or with missing key values or with diabetes and kidney diseases. Questionnaire survey, body composition and calcaneus bone mineral density were conducted. The relation of fat mass percentage (FMP), trunk to total fat ratio (TrTFR), trunk to limb fat ratio (TrLFR), limb to total fat ratio (LTFR) and viscera to total fat ratio (VTFR) with calcaneus BMD were assessed using the multivariate linear regression models after adjusting for possible confounding effects. The central fat distribution types were divided into 4 groups including type 1: both trunk fat and visceral fat greater than the sex-and age-specific internal P(75); type 2: barely trunk fat greater than P(75); type 3: barely visceral fat greater than P(75); type 4: both trunk fat and visceral fat greater than P(75). The central fat distribution types were included into the model in the form of dummy variables to analyze its relationship with calcaneal BMD. The sex-and age-specific z-scores of fat distribution indicators and BMD were calculated. Results: A total of 15 030 participants aged (11.4±3.3) years (50.2% boys) were involved in the analysis. In both genders, after adjusting for age, height, lean mass index, smoking, drinking, physical activity, milk intake, vitamin D and calcium supplementation, FMP, TrTFR, TrLFR and VTFR were negatively correlated with calcaneal BMD (all P value<0.05), while LTFR was positively associated with calcaneal BMD (all P values<0.05). Compared to the central fat distribution type 1, the regression coefficients (95% CI) of type 2, 3 and 4 were -0.253 (-0.418, -0.087), -0.385 (-0.567, -0.204) and -0.428 (-0.487, -0.369) in boys, respectively; the regression coefficients (95% CI) of type 3 and 4 were -0.158 (-0.301, -0.015) and -0.226 (-0.290, -0.163), respectively. Conclusion: Body fat distribution and central fat distribution in children and adolescents were correlated with calcaneus bone mineral density.

Initial systemic inflammatory state perturbs exercise training adaptations in elite Taekwondo athletes.

PURPOSE: This study examined ten-week TKD-specific training effects on aerobic capacity, body composition, hormone responses and hematological parameters in elite TKD athletes with varied initial inflammatory states. METHODS: Twenty-two elite college TKD athletes were divided into two groups according to their initial neutrophils-to-lymphocytes ratio (NLR) values: Low NLR (N = 11, 9M/2F, age: 21.6 ± 1.0 yrs; NLR: 1.3 ± 0.2) and High NLR (N = 11, 8M/3F, age: 22.0 ± 0.7 yrs, NLR: 2.5 ± 1.3), and participated in a 10-week TKD-specific training program. Aerobic capacity, body composition, hormonal responses and hematological parameters were measured at baseline and 10-weeks after TKD training. RESULTS: VO2max and shuttle run distance were significantly increased in both groups after training. However, the degree of improvement was greater in the Low NLR group than in the High NLR group. After 10-weeks of exercise training, the High NLR group presented markedly higher fat mass percentage and visceral fat area and significantly lowers DHEA-S to cortisol ratio (D/C ratio) than the Low NRL group. The post-training NLR was negatively correlated with the D/C ratio. Neutrophil counts and NLR were still significantly higher in the High NLR group after training. CONCLUSIONS: This study provides new evidence that young elite TKD athletes with slightly high baseline systemic inflammatory state appear to perturb adaptations to exercise training.

Body composition after bone marrow transplantation in childhood.

PURPOSE/OBJECTIVES: To describe the body composition and fat distribution of childhood bone marrow transplantation (BMT) survivors at least one year post-transplantation and examine the ability of the Centers for Disease Control and Prevention criteria to identify survivors with elevated body fat percentage. DESIGN: Cross-sectional, descriptive. SETTING: Pediatric oncology program at a National Cancer Institute-designated comprehensive cancer center. SAMPLE: 48 childhood BMT survivors (27 males and 21 females). METHODS: Measurements included dual-energy x-ray absorptiometry scan, height, weight, and physical activity. Descriptive statistics were reported and mixed-model linear regression models were used to describe findings and associations. MAIN RESEARCH VARIABLES: Total body fat percentage and central obesity (defined as a ratio of central to peripheral fat of 1 or greater). FINDINGS: Fifty-four percent of survivors had body fat percentages that exceeded recommendations for healthy body composition and 31% qualified as having central obesity. Previous treatment with total body irradiation was associated with higher body fat percentage and central obesity, and graft-versus-host disease was associated with lower body fat percentage. The body mass index (BMI) criteria did not correctly identify the BMT survivors who had elevated body fat percentage. CONCLUSIONS: Survivors of childhood BMT are at risk for obesity and central obesity that is not readily identified with standard BMI criteria. IMPLICATIONS FOR NURSING: Nurses caring for BMT survivors should include evaluation of general and central obesity in their assessments. Patient education materials and resources for healthy weight and muscle building should be made available to survivors. Research is needed to develop appropriate interventions.