TY  - JOUR
A1  - Fühner, Thea Heidi
A1  - Granacher, Urs
A1  - Golle, Kathleen
A1  - Kliegl, Reinhold
T1  - Age and sex effects in physical fitness components of 108,295 third graders including 515 primary schools and 9 cohorts
JF  - Scientific Reports
N2  - Children’s physical fitness development and related moderating effects of age and sex are well documented, especially boys’ and girls’ divergence during puberty. The situation might be different during prepuberty. As girls mature approximately two years earlier than boys, we tested a possible convergence of performance with five tests representing four components of physical fitness in a large sample of 108,295 eight-year old third-graders. Within this single prepubertal year of life and irrespective of the test, performance increased linearly with chronological age, and boys outperformed girls to a larger extent in tests requiring muscle mass for successful performance. Tests differed in the magnitude of age effects (gains), but there was no evidence for an interaction between age and sex. Moreover, “physical fitness” of schools correlated at r = 0.48 with their age effect which might imply that "fit schools” promote larger gains; expected secular trends from 2011 to 2019 were replicated.
Y1  - 2021
U6  - https://doi.org/10.1038/s41598-021-97000-4
SN  - 2045-2322
VL  - 11
SP  - 1
EP  - 13
PB  - Nature Portfolio
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Fühner, Thea Heidi
A1  - Granacher, Urs
A1  - Golle, Kathleen
A1  - Kliegl, Reinhold
T1  - Effect of timing of school enrollment on physical fitness in third graders
JF  - Scientific Reports
N2  - Timing of initial school enrollment may vary considerably for various reasons such as early or delayed enrollment, skipped or repeated school classes. Accordingly, the age range within school grades includes older-(OTK) and younger-than-keyage (YTK) children. Hardly any information is available on the impact of timing of school enrollment on physical fitness. There is evidence from a related research topic showing large differences in academic performance between OTK and YTK children versus keyage children. Thus, the aim of this study was to compare physical fitness of OTK (N = 26,540) and YTK (N = 2586) children versus keyage children (N = 108,295) in a representative sample of German third graders. Physical fitness tests comprised cardiorespiratory endurance, coordination, speed, lower, and upper limbs muscle power. Predictions of physical fitness performance for YTK and OTK children were estimated using data from keyage children by taking age, sex, school, and assessment year into account. Data were annually recorded between 2011 and 2019. The difference between observed and predicted z-scores yielded a delta z-score that was used as a dependent variable in the linear mixed models. Findings indicate that OTK children showed poorer performance compared to keyage children, especially in coordination, and that YTK children outperformed keyage children, especially in coordination. Teachers should be aware that OTK children show poorer physical fitness performance compared to keyage children.
Y1  - 2022
U6  - https://doi.org/10.1038/s41598-022-11710-x
SN  - 2045-2322
VL  - 12
SP  - 1
EP  - 11
PB  - Springer Nature
CY  - London
ER  -