The association between physical fitness and age-related differences in cognition and brain structure has been studied fairly extensively during development and aging, yet comparatively less in young adulthood. The current study examined 1,195 young adults aged 22 to 36 (54% female; 67% Caucasian) to better understand associations between physical fitness-grip strength and submaximal cardiovascular endurance-and age-related differences in executive function (EF), memory, and average cortical thickness. EF, memory, and cortical thickness were negatively associated with age, and higher endurance was positively associated with EF and memory. Neither physical fitness measure associated with cortical thinning. To follow-up on these analyses, data from monozygotic (n = 149 pairs) and dizygotic (n = 93 pairs) twins were used to estimate the degree to which heritability versus environment might contribute to the observed associations between cognition and endurance. Environmental effects shared by monozygotic and dizygotic twins alike were estimated to account for roughly 50% of the correlation between endurance and cognition (EF and memory). Heritability and nonshared environmental effects were inconsistent across EF and memory. Overall, these findings suggest an association between cardiovascular endurance and age-related differences in cognition in young adulthood and that these associations may be independent of cortical thinning. Whereas there was consistent evidence for a moderate contribution of the shared environment, there was limited and inconsistent evidence for a role of heritability. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

中文翻译：

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青少年时期的身体健康和认知和皮质厚度的年龄相关差异。

身体健康与认知和大脑结构的年龄相关差异之间的关联在发育和衰老过程中得到了相当广泛的研究，但在青年时期则相对较少。目前的研究调查了 1,195 名 22 至 36 岁的年轻人（54% 女性；67% 白种人），以更好地了解身体素质-握力与次最大心血管耐力以及与年龄相关的执行功能（EF）、记忆力和平均皮质厚度。EF、记忆力和皮质厚度与年龄呈负相关，较高的耐​​力与 EF 和记忆力呈正相关。两种体能测量都与皮质变薄无关。为了跟进这些分析，来自单卵（n = 149 对）和异卵（n = 93 对）双胞胎的数据用于估计遗传与环境对观察到的认知和耐力之间关联的影响程度。据估计，单卵双胞胎和异卵双胞胎所共有的环境影响约占耐力和认知（EF 和记忆）之间相关性的 50%。遗传力和非共享环境影响在 EF 和内存中不一致。总体而言，这些发现表明心血管耐力与年轻成年期认知的年龄相关差异之间存在关联，并且这些关联可能与皮质变薄无关。虽然有一致的证据表明共享环境的贡献适中，关于遗传性的作用，证据有限且不一致。（PsycInfo 数据库记录 (c) 2020 APA，保留所有权利）。