Associations of physical fitness with cortical inhibition and excitation in adolescents and young adults

Hanna Mari Skog; Sara Määttä; Laura Säisänen; Timo A Lakka; Eero A Haapala

doi:10.3389/fnins.2024.1297009

Associations of physical fitness with cortical inhibition and excitation in adolescents and young adults

Front Neurosci. 2024 Apr 29:18:1297009. doi: 10.3389/fnins.2024.1297009. eCollection 2024.

Authors

Hanna Mari Skog¹, Sara Määttä², Laura Säisänen^{2

3}, Timo A Lakka^{1

4

5}, Eero A Haapala^{1

6}

Affiliations

¹ Department of Physiology, Institute of Biomedicine, School of Medicine, University of Eastern Finland, Kuopio, Finland.
² Department of Clinical Neurophysiology, Diagnostic Imaging Center, Kuopio University Hospital, Kuopio, Finland.
³ Department of Technical Physics, University of Eastern Finland, Kuopio, Finland.
⁴ Kuopio Research Institute of Exercise Medicine, Kuopio, Finland.
⁵ Department of Clinical Physiology and Nuclear Medicine, Kuopio University Hospital, University of Eastern Finland, Kuopio, Finland.
⁶ Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland.

Abstract

Objective: We investigated the longitudinal associations of cumulative motor fitness, muscular strength, and cardiorespiratory fitness (CRF) from childhood to adolescence with cortical excitability and inhibition in adolescence. The other objective was to determine cross-sectional associations of motor fitness and muscular strength with brain function in adolescence.

Methods: In 45 healthy adolescents (25 girls and 20 boys) aged 16-19 years, we assessed cortical excitability and inhibition by navigated transcranial magnetic stimulation (nTMS), and motor fitness by 50-m shuttle run test and Box and block test, and muscular strength by standing long jump test. These measures of physical fitness and CRF by maximal exercise were assessed also at the ages 7-9, 9-11, and 15-17 years. Cumulative measures of physical measures were computed by summing up sample-specific z-scores at ages 7-9, 9-11, and 15-17 years.

Results: Higher cumulative motor fitness performance from childhood to adolescence was associated with lower right hemisphere resting motor threshold (rMT), lower silent period threshold (SPt), and lower motor evoked potential (MEP) amplitude in boys. Better childhood-to-adolescence cumulative CRF was also associated with longer silent period (SP) duration in boys and higher MEP amplitude in girls. Cross-sectionally in adolescence, better motor fitness and better muscular strength were associated with lower left and right rMT among boys and better motor fitness was associated with higher MEP amplitude and better muscular strength with lower SPt among girls.

Conclusion: Physical fitness from childhood to adolescence modifies cortical excitability and inhibition in adolescence. Motor fitness and muscular strength were associated with motor cortical excitability and inhibition. The associations were selective for specific TMS indices and findings were sex-dependent.

Keywords: adolescence; motor fitness; motor threshold; muscular strength; transcranial magnetic stimulation.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. The FitBrain study has been financially supported by the Juho Vainio Foundation. The PANIC study has been supported financially by grants from the Ministry of Education and Culture of Finland, the Academy of Finland, the Ministry of Social Affairs and Health of Finland, Research Committee of the Kuopio University Hospital Catchment Area (State Research Funding), Finnish Innovation Fund Sitra, Social Insurance Institution of Finland, Finnish Cultural Foundation, Foundation for Paediatric Research, Diabetes Research Foundation in Finland, Finnish Foundation for Cardiovascular Research, Juho Vainio Foundation, Paavo Nurmi Foundation, Yrjö Jahnsson Foundation, and the city of Kuopio. The sponsors had no role in designing the study, the collection, analysis or interpretation of the data, the writing of the report, or the decision to submit the article for publication. HS received funding support from the Niilo Helander Foundation, Jenny and Antti Wihuri Foundation, Juho Vainio Foundation, and the Orion Research Foundation sr.