This study was designed to examine the associations between physical fitness and grey matter volume of cerebellar lobules related to cognition in adolescents, and whether these associations differed between males and females. The analysis was based on the FitBrain Study involving 40 participants with a mean age of 17.9 years old with 8-year follow-up examinations from the Physical Activity and Nutrition in Children Study (PANIC).
Cerebellar volumes were assessed using magnetic resonance imaging technology. Cardiorespiratory fitness was assessed with a maximal ramp test on a cycle ergometer, and muscular strength was assessed with standing long jump. Speed agility was assessed with the 10 x 5 shuttle run test, and coordination was assessed with the Box and Block Test. Finally, neuromuscular fitness was assessed as the sum of the standing long jump, Box and Block Test, and shuttle test z-scores.
The researchers report that adolescents with better neuromuscular fitness since childhood had larger Crus I grey matter volume, but those with better cardiorespiratory fitness had smaller total cerebellar grey matter volume. Additionally, males with better neuromuscular fitness since childhood had smaller Crus II grey matter volume.
“Our study highlights the importance of physical activity through childhood and adolescence, leading to better physical fitness, as it might be relevant to cerebellar volumes related to cognition and learning. However, the associations we observed are in part contradictory,” says Doctoral Researcher Petri Jalanko from the Faculty of Sport and Health Sciences at the University of Jyväskylä.
“The study sheds light on the associations between physical fitness and the cerebellum. Future randomised controlled trials utilising direct cardiorespiratory fitness measurements and novel brain imaging to assess a larger population and both sexes separately are needed to better understand the associations and causality between physical fitness and cerebellar volumes in adolescents,” Jalanko says.
