1.
Total and regional bone mineral and tissue composition in female adolescent athletes: comparison between volleyball players and swimmers.
Valente-Dos-Santos, J, Tavares, ÓM, Duarte, JP, Sousa-E-Silva, PM, Rama, LM, Casanova, JM, Fontes-Ribeiro, CA, Marques, EA, Courteix, D, Ronque, ERV, et al
BMC pediatrics. 2018;(1):212
Abstract
BACKGROUND Exploring the osteogenic effect of different bone-loading sports is particular relevant to understand the interaction between skeletal muscle and bone health during growth. This study aimed to compare total and regional bone and soft-tissue composition between female adolescent swimmers (n=20, 15.71±0.93 years) and volleyball players (n=26, 16.20±0.77 years). METHODS Dietary intake was obtained using food frequency questionnaires. Body size was given by stature, sitting height, and body mass. Six skinfolds were measured. Bone mineral content (BMC) and density (BMD), lean soft tissue, and fat tissue were assessed using dual-energy X-ray absorptiometry. Pearson's product moment correlation coefficients were calculated to examine the relationships among variables, by type of sport. Comparisons between swimmers and volleyball players were performed using student t-tests for independent samples and multivariate analysis of covariance (controlling for age, training history and body size). RESULTS Swimmers (BMC: 2328±338 g) and volleyball players (BMC: 2656±470 g) exceeded respectively by 2.1 and 2.8 standard deviation scores the average of international standards for whole body BMC of healthy adolescents. Years of training in swimmers were positively related to the upper limbs BMC (r=+0.49, p<0.05). In volleyball players, years of training correlated significantly with lower limbs BMD (r=+0.43, p<0.05). After adjustments for potential confounders, moderate differences (ES-r=0.32) between swimmers and volleyball players were noted in BMD at the lower limbs (volleyball players: +0.098 g∙cm-2, +7.8%). CONCLUSIONS Youth female athletes who participate in high-intensity weight-loading activities such as volleyball exhibit moderately higher levels of BMD at the lower limbs compared to non-loading sports such as swimming.
2.
Decreased Circulating mtDNA Levels in Professional Male Volleyball Players.
Nasi, M, Cristani, A, Pinti, M, Lamberti, I, Gibellini, L, De Biasi, S, Guazzaloca, A, Trenti, T, Cossarizza, A
International journal of sports physiology and performance. 2016;(1):116-21
Abstract
PURPOSE Exercise exerts various effects on the immune system, and evidence is emerging on its anti-inflammatory effects; the mechanisms on the basis of these modifications are poorly understood. Mitochondrial DNA (mtDNA) released from damaged cells acts as a molecule containing the so-called damage-associated molecular patterns and can trigger sterile inflammation. Indeed, high plasma levels of mtDNA are associated to several inflammatory conditions and physiological aging and longevity. The authors evaluated plasma mtDNA in professional male volleyball players during seasonal training and the possible correlation between mtDNA levels and clinical parameters, body composition, and physical performance. METHODS Plasma mtDNA was quantified by real-time PCR every 2 mo in 12 professional volleyball players (PVPs) during 2 consecutive seasons. As comparison, 20 healthy nonathlete male volunteers (NAs) were analyzed. RESULTS The authors found lower levels of mtDNA in plasma of PVPs than in NAs. However, PVPs showed a decrease of circulating mtDNA only in the first season, while no appreciable variations were observed during the second season. No correlation was observed among mtDNA, hematochemical, and anthropometric parameters. CONCLUSIONS Regular physical activity appeared associated with lower levels of circulating mtDNA, further confirming the protective, anti-inflammatory effect of exercise.