Influence of Biological Maturity on the Muscular Strength of Young Male and Female Swimmers

Abstract

The present study compared the evolution of strength and muscle mass in swimmers of both sexes across different chronological and biological ages. Seventy-six swimmers (55 males and 21 females) from 10 to 20 years of age underwent evaluations of sexual maturation using the developmental stage of the genitals (G1, G2, G3 G4 and G5) and pubic hair (P1, P2, P3, P4 and P5) (Tanner criteria), lean mass using the dual-energy X-ray absorptiometry method, and isokinetic strength of the knee extensor muscles. Boys did not present a significant difference in strength among G1, G2, and G3 (p > 0.05) nor between 10 and 13 years of age (p > 0.05), although significant differences in strength of the extensor (p = 0.038) muscles of the knee were found between G3 and G4 and between athletes of 10 and 14 years of age (extensor muscles, p = 0.033). Muscle mass was different between G3 and G4 (p = 0.003) and between 10 and 14 years of age (p = 0.020). The mean age of boys in the G4 pubertal stage was 13.7 ± 2.0 years, although from 12 to 16 years of age, boys are typically in the G4 stage. Girls showed no significant differences in strength nor muscle mass among the pubertal stages (p > 0.05). We conclude that by equating boys by chronological age, individuals with different pubertal development levels, muscle mass, and strength levels can be grouped. Therefore, the relationship between the level of pubertal deve-lopment and chronological age seems to be a useful strategy for grouping boys, while grouping girls by chronological age seems adequate for training and competition.

Influência do sexo no pico de torque isométrico da flexo-extensão de cotovelo de indivíduos na puberdade

“…Estudos com maior tamanho amostral estão em andamento. 2 A influencia de outros fatores potencialmente modificadores do torque isométrico, tais como fatores socioeconômicos e nível de atividade não foram controlados.…”

“…Assim, é importante para entender o desempenho muscular ao longo do desenvolvimento biológico do indivíduo. 2 Dentro da avaliação do desempenho muscular, o torque muscular isométrico é uma variável que pode ser obtido por dinamômetros portáteis quando se considera o comprimento do segmento corporal multiplicando-o pela força. 3 Entretanto, o padrão ouro para avaliar torque é o dinamômetro isocinético 4 que fornece dados numéricos e gráficos.…”

“…Desencadeou quarentena, isolamento social, dificuldades econômicas, medo em contrair uma doença potencialmente letal e prejuízo na qualidade de vida de diversas pessoas. 2 Quando a quarentena foi declarada, simultaneamente levou a suspensão dos atendimentos presenciais de tratamentos de reabilitação em grandes centros. A Organização das Nações Unidas (ONU), aponta que as pessoas com deficiência estão entre as mais…”

Effect of Sex and Maturation on Knee Extensor and Flexor Strength in Adolescent Athletes

“…31 More recently, a study of 40 prepubertal and 40 postpubertal children and adolescents found that knee extensor and flexor strength is higher in boys, but only at the postpubertal stage, 29 a finding that was confirmed by a study on swimmers that assessed only knee extensor strength. 4 All 4 studies were based on cross-sectional data collected at 1 time point rather than longitudinal changes in muscle strength in young athletes over time. In terms of longitudinal studies, 1 study included male participants only, 10 while another study 16 on 8- to 15-year-old participants compared boys and girls of similar biological age instead of considering maturation, and found that the knee flexors and extensors of boys were stronger at ages 14 and 15 years only.…”