Consumo alimentar e perfil antropométrico de tenistas amadores e profissionais

PERDA ELETROLÍTICA DE CÁLCIO, MAGNÉSIO E FERRO NO SUOR DURANTE CORRIDA EM ESTEIRA

RESUMO Introdução: O suor e sua consequente evaporação são fundamentais para manutenção da temperatura corporal durante o exercício. Objetivo: Avaliar a perda de cálcio (Ca++), magnésio (Mg++) e ferro (Fe++) no suor de corredores e de indivíduos ativos. Métodos: Foram avaliados 15 atletas corredores de fundo {VO2máx = 68 ± 5,4 ml(kg.min)-1} e 15 indivíduos ativos não atletas {VO2máx = 50,3 ± 6,3 ml(kg.min)-1}, com média de idade, respectivamente, de 25,3 ± 2,4 e 23,1 ± 4,3 anos. Ambos os grupos se exercitaram por 80 minutos em esteira, com intensidade de 75% a 85% da frequência cardíaca de reserva, e ingeriram 3 ml de água/kg de peso corporal a cada 15 minutos. As condições ambientais da prova foram 21,9 ± 1,5 °C e 89,2 ± 5,6% de umidade relativa para os atletas e 21,8 ± 1,6 °C e 93,2 ± 3,5% de UR para os ativos. As amostras de suor foram coletadas em intervalos regulares de 20 minutos nas regiões do peito, torácica e lombar das costas, para posterior análise dos minerais Ca++, Mg++ e Fe++ por espectrofotômetro de absorção atômica. Resultados: Não foram registradas diferenças significativas para os minerais em função do nível de condicionamento. Observou-se tendência à diminuição na concentração do Mg++ e Fe++ do suor ao longo do exercício. Conclusão: Nas condições ambientais e de exercício estudadas, o condicionamento não interfere na perda de Ca++, Mg++ e Fe++.

Does carbohydrate supplementation enhance tennis match play performance?

BACKGROUND

Carbohydrate (CHO) ingestion may be an interesting approach to avoid significant decrement to the tennis match performance. The aim of the present investigation was to assess the effects of CHO supplementation on tennis match play performance.

METHODS

Twelve young tennis players (18.0 ± 1.0 years; 176 ± 3.4 cm; 68.0 ± 2.3 kg; body fat: 13.7 ± 2.4%) with national rankings among the top 50 in Brazil agreed to participate in this study, which utilized a randomized, crossover, double blind research design. The experiment was conducted over a 5-day period in which each player completed two simulated tennis matches of a 3-hour duration. The players received either a CHO or a placebo (PLA) drinking solution during simulated tennis matches. Athlete's performance parameters were determined by filming each match with two video cameras. Each player was individually tracked for the entire duration of the match to measure the following variables: (1) games won; (2) rally duration; (3) strokes per rally; (4) effective playing time (%); (5) aces; (6) double faults; (7) first service in; (8) second service in; (9) first return in and (10) second return in.

RESULTS

There were no differences between trials in any of the variables analyzed.

CONCLUSIONS

CHO supplementation did not improve tennis match play performance under the present experimental conditions.

The prevalence of disordered eating and possible health consequences in adolescent female tennis players from Rio de Janeiro, Brazil

The aim of this study was to estimate the prevalence of disordered eating and possible health consequences in adolescent female tennis players. This cross-sectional controlled study investigated the pubertal development (Tanner stages); body composition (dual energy X-ray absorptiometry-DXA); dietary intake (food record); presence of disordered eating (EAT-26, BITE and BSQ); menstrual status (questionnaire) and bone mineral density (DXA). The Female Athlete Triad (FAT) was divided into two severity stages. The study included 45 adolescents (24 athletes and 21 controls) at some pubertal developmental stage. The athletes exhibited better body composition profiles. We found that 91.7%, 33.3% and 25% of athletes and 71.4%, 9.5% and 33.3% of controls met criteria for disordered eating and/or low energy availability, menstrual irregularities and low bone mass, respectively. A greater percentage of athletes than controls presented with 1 and 2 FAT components (stage I), and 4.2% presented with the full syndrome. In conclusion, tennis players appear to present with more severe disorders than controls and should be monitored to avoid damage to their performance and health.