The aim of the current study was to assess phase angle (PA) and bioelectrical impedance vectors (BIVA) in adolescent (n = 105, 12–19 y) and adult (n = 90, 20–50 y) male athletes practicing varied sports modalities. Bioelectrical impedance analysis (BIA) was performed with a single-frequency tetrapolar impedance analyzer after the athletes had fasted overnight for 8 h. PA and BIVA were determined from BIA data. PA presented correlations (P < .01) with body-mass index (r = .58) in all athletes and also with age in adolescent (r = .63) and adult (r = –.27) athletes. Compared with adults, adolescent athletes presented lower PA and higher frequency of PA below the 5th percentile of a reference population (P < .001). The adolescents with low PA were mostly football and basketball players. The BIVA confidence ellipses of adult and adolescent athletes were different (P < .001) between them and from their respective reference populations and were closer than those of adult and adolescent nonathletes. About 80% of the athletes were in the 95th percentile of BIVA tolerance ellipses and in quadrants consistent with adequate body cell mass and total body water. The adolescent athletes outside the 95th percentile ellipse were all football and basketball players who showed indications of decreased water retention and body cell mass and of increased water retention, respectively. PA and BIVA ellipses showed that the intense training routine of the athletes changed functional and hydration parameters and that the magnitude of these changes in adolescents may depend on the sport modality practiced.
Josely C. Koury, Nádia M.F. Trugo and Alexandre G. Torres
Josely C. Koury, Astrogildo V. de Oliveira Jr., Emílson S. Portella, Cyntia F. de Oliveira, Gustavo C. Lopes and Carmen M. Donangelo
The purpose of this study was lo compare zinc and copper biochemical indices of antioxidant status and their relationship in elite athletes of different modalities: aerobic with high-impact (triathletes, n = 10 and long-distance runners, n = 12), anaerobic with high-impact (short-distance runners, n = 9), and anaerobic with low-impact (short-distance swimmers, n = 13). The influence of recent dietary intake and body composition was also evaluated. A venous blood sample was drawn 16-20 hr after competition for the following measurements: packed-cell volume and hemoglobin in blood; copper and zinc in plasma and erythrocytes; ceruloplasmin in plasma; superoxide dismutase activity and metal-lothionein in erythrocyles; and erythrocyte osmotic fragility. Zinc and copper intakes were not different in the athlete groups and did not affect the biochemical indices measured. Athletes of the long-distance high-impact aerobic modalities had higher indices of antioxidant protection (erythrocyte zinc, superoxide dismutase activity, and metallothionein) than those of the short-distance low-impact modalities, suggesting that there is adaptation of the antioxidant capacity to the specific training. Significant correlations were observed in all athletes between erythrocyte zinc, superoxide dismutase activity, and metallothionein consistent with the importance of an adequate zinc status in the response of antioxidant mechanisms to intense exercise.