Objectives: To investigate the effects of different sports on the incidence of traumatic fractures (TF; sport-related fractures and those occurring in daily activities) among adolescents during the 9-month follow-up period. Methods: The adolescents were contacted in 11 different locations (3 public/private schools and 8 sports clubs), and the final sample was divided into 3 groups: control (n = 121), swimming (n = 51), and impact sports (n = 142). The incidence of TF was calculated by considering the exposure to sports (TF/1000 h). Results: In the overall sample, the incidence of TF was 1.29 TF/1000 hours of sports exposure, while the incidence of sport-related TF was 0.39 TF/1000 hours of sports exposure. Adolescents engaged in sports (P = .004), independently of type (P = .001), for 3 or more days per week (P = .004) and more than 60 minutes per day (P = .001) had lower incidence of TF. Adolescents engaged in more than 300 minutes per week of sport (0.17 TF/1000 h) had lower incidence than those who did not (2.06 TF/1000 h [P = .001]). A similar finding was observed for sport-related TF (≥300 min/wk: 0.08 TF/1000 h vs 300 min/wk: 0.615 TF/1000 h [P = .02]). Conclusion: Adolescents engaged in sports showed a lower incidence of TF than nonengaged adolescents.
Kyle R. Lynch, Michael Fredericson, Bruna Turi-Lynch, Ricardo R. Agostinete, Igor H. Ito, Rafael Luiz-de-Marco, Mario A. Rodrigues-Junior and Rômulo A. Fernandes
Diego G.D. Christofaro, Bruna C. Turi-Lynch, Kyle R. Lynch, William R. Tebar, Rômulo A. Fernandes, Fernanda G. Tebar, Gregore I. Mielke and Xuemei Sui
Background: This study investigated associations between different types of sedentary behavior (SB) and physical activity (PA) in parent and their child, including the moderating effects of parent and child sex. Methods: In total, 1231 adolescents, 1202 mothers, and 871 fathers were evaluated. The SB (TV viewing + computer + video game); different types of PA (leisure-time PA, occupational PA, and total PA); and the socioeconomic level were evaluated by questionnaire. The relationship between adolescents’ SB and PA with parental characteristics was estimated by linear regression. Results: The SB of male adolescents was correlated to the father’s SB (β = 0.26; 95% confidence interval [CI], 0.13–0.39) and mother’s SB (β = 0.18; 95% CI, 0.06–0.31). A similar relationship was observed between SB of female adolescents and the father’s SB (β = 0.31; 95% CI, 0.19–0.42) and mother’s SB (β = 0.29; 95% CI, 0.20–0.38]). The SB of girls was inversely related to mother’s occupational PA (β = −2.62; 95% CI, −3.66 to −0.53]). The PA of the boys and girls was correlated with their fathers and mothers PA. All the results were adjusted for age and parent’s socioeconomic level. Conclusions: SB and PA of parents were associated with SB and PA of their children, regardless of gender. Strategies for health promotion should consider the family environment to increase PA and reduce SB.
Ricardo Ribeiro Agostinete, Santiago Maillane-Vanegas, Kyle R. Lynch, Bruna Turi-Lynch, Manuel J. Coelho-e-Silva, Eduardo Zapaterra Campos, Suziane Ungari Cayres and Romulo Araújo Fernandes
Purpose: To investigate the mediating effect of muscle mass on the relationship between training load and bone density in adolescent swimmers. Methods: A cross-sectional study involving 87 control and 22 swimmers aged 10–19 years (overall sample: n = 109). Swimmers had a minimum of 1 year of competition in regional and national championships, and control adolescents reported 1 year without any organized sport. Bone density was the main outcome (dual-energy X-ray absorptiometry), which was measured in upper limbs, lower limbs, spine, and whole body. Monthly training load was the independent variable, while the mediation effect of lean soft tissue was assessed. Maturity offset, age, inflammation, and vitamin D intake were treated as covariates. Results: Swimmers had lower bone density than controls; there was a significant and positive relationship between training load and muscle mass. In boys, training load presented a negative correlation with bone density in lower limbs [r = −.293; 95% confidence interval (CI), −.553 to −.034]. In girls, training load was negatively related to bone mineral density in lower limbs (r = .563; 95% CI, −.770 to −.356) and whole body (r = −.409; 95% CI, −.609 to −.209). Conclusion: Training load had a negative relationship on bone density of swimmers of both sexes, independently of the positive effect of lean soft tissue on bone density.
Igor H. Ito, Han C.G. Kemper, Ricardo R. Agostinete, Kyle R. Lynch, Diego G.D. Christofaro, Enio R. Ronque and Rômulo A. Fernandes
Purpose: To compare bone mineral density (BMD) gains in adolescents of both genders stratified according to different martial art styles in a 9-month follow-up study. Methods: The longitudinal study consisted of 29 adolescents of both genders and age between 11 and 17 years stratified into a control group (not engaged in any sport) and 50 fighters (kung fu/karate, n = 29; judo, n = 21). All 79 subjects underwent anthropometric measures (weight, height, leg length, and height set) and dual-energy X-ray absorptiometry (BMD, in g/cm2) at 2 moments, baseline and 9 months later. Maturity offset (age at peak height velocity), lean soft tissue, chronological age, and resistance training were treated as covariates. Results: Male judoists presented higher gains in BMD-spine [0.098 g/cm2 (95% confidence interval, 0.068–0.128)] than control group [0.040 g/cm2 (95% confidence interval, 0.011–0.069)] (post hoc test with P = .030). There was no effect of martial art on BMD gains among girls. Independently of gender, in all multivariate models, lean soft tissue constituted the most relevant covariate. Conclusions: Judo practice in adolescents affected the bone accrual significantly after 9-month follow-up compared with controls, mainly in boys.