Relationships of sex hormones with muscle mass and muscle strength in male adolescents at different stages of puberty

Abstract

This study analysed the associations of sex steroids with fat-free mass (FFM) and handgrip strength in 641 Chinese boys. Serum total testosterone (TT) and oestradiol were measured by chemiluminescence immunoassay. Free testosterone (FT) and oestradiol were calculated. FFM and handgrip strength were measured by bioelectrical impedance analysis and a hand dynamometer, respectively. Generalised additive models and multiple linear regression were used to explore the relationships. A subgroup analysis was conducted in early-mid pubertal and late-post pubertal groups. Age, height, weight, physical activity, intake of dietary protein and/or stage of puberty were adjusted. TT and FT were positively related to FFM and handgrip strength, with a curvilinear relationship being detected for handgrip strength (p<0.050). This curvilinear relationship was only observed in the late-post pubertal group, suggesting a potential threshold effect (FT>11.99ng/dL, β = 1.275, p = 0.039). In the early-mid pubertal group, TT and/or FT were linearly or near-linearly related to FFM or handgrip strength (β = 0.003–0.271, p<0.050). The association between FT and FFM was stronger than that in the late-post pubertal group. This study found that serum T had different associations with muscle parameters in Chinese early-mid pubertal and late-post pubertal boys. In the late-post pubertal boys, serum T was curvilinearly related to muscle strength with a threshold effect and its link with muscle mass was weaker.

Teacher-Rated Executive Functions, Gender and Relative Age: Independent and Interactive Effects on Observed Fundamental Motor Skills in Kindergarteners

“…At this stage of life, adolescence, a significant concentration of testosterone is produced in boys that contributes to creating bigger and stronger bones, as well as greater muscle mass and strength. This produces a significant improvement in their motor skills, generating differences with respect to girls ( Xu et al, 2021 ). However, in stages prior to adolescence, the absence of important physical differences for motor skills would explain why boys and girls, in most FMS tasks, show similar performance.…”

Anterior Cruciate Ligament Rehabilitation for the 10- to 18-Year-Old Adolescent Athlete: Practice Guidelines Based on International Delphi Consensus

“… 5 The increase in hormones will give boys a boost through strengthening, while girls may add fat mass during puberty, which reduces strength relative to body weight. 27 , 30 Strength gains in prepubertal athletes will be slower and mainly due to an increase in the number of motor neurons that are recruited with each contraction, while in mid- and postpubertal athletes, strength gains are more likely associated with muscle hypertrophy. 20 Therefore, the panel members reached a consensus (80%) about midpubertal athletes being treated similarly to postpubertal athletes when it comes to resistance training.…”

Mediation effects of lean mass and fat mass on the relationship between body mass index and handgrip strength

“…It is important to emphasize that, despite the limitations of the small sample size, the results of this study provide a solid foundation for future research and may have significant implications in the context of growth, exercise, and health. Furthermore, it was not possible to collect information on sex hormones, which are related to gains in muscle mass and strength during the growth period (Xu et al, 2021). Considering sexual (Bim, Pinto, Scarabelot, et al, 2021; Silva et al, 2017), pubertal (Goswami et al, 2014; Manzano‐Carrasco et al, 2022), and physical activity (Bim, Pinto, Scarabelot, et al, 2021; Mateo‐Orcajada et al, 2022) differences in body composition and muscle strength, these variables were included as covariates in the mediation models to control potential confounding effects in the analyses.…”