Interrelations of Physical Fitness and Cognitive Functions in German Schoolchildren

Abstract

This study investigated the relationship between different levels of physical fitness and cognitive functions in boys and girls. Schoolchildren from a comprehensive school in Germany (n = 211, 39% girls, 5th and 6th grade) attended regular or sport-focused classes with different numbers of physical education (PE) classes per week (3 vs. 5-6 h). Performance of physical fitness was tested according to endurance, strength, speed, coordination and flexibility. Four computerized instruments (switch task, 2-back task, Corsi block-tapping task and flanker task) were used to test cognitive functions. Additional predictors, sex, age, PE class, Body Mass Index and physical activity, were included in analyses. The results showed that physical fitness was associated with improved attention and memory functions in children, although the associations were mostly small. After Bonferroni correction, mainly coordination was related to improved cognition. Physical activity, i.e., step counts, PE class and sex were associated with specific cognitive outcomes. These findings may be important for effective health promotion, and supporting children's education in the school environment. Sex-specific physical activities in school could potentially lead to greater cognitive benefits in children. Randomized trials are needed to replicate these results.

Keywords: cognition; coordination; physical activity; physical education; physical fitness; school-aged children.

Figure 1

Physical fitness tests via the German Motor Test 6–18 (DMT 6–18). Performance: (A) Speed via 20-m sprint; (B) Endurance via 6-min run; (C) Flexibility via forward bending; (D) Coordination of the jumping; (E) Coordination of the backward balancing; (F) Strength of the abdominal muscles via sit-ups; (G) Strength of the lower extremities via jumping ability; (H) Strength of the upper extremities via push-ups; DMT, Deutscher Motorik-Test.

Figure 2

Cognitive task. (A). Visual attention and switching abilities between two targets: numbers and letters, measured by task switching. The task is comprised of three sections. 1. First section, numbers (non-switch). Numbers had to be clicked in ascending order with the mouse cursor. 2. Second section, letters (non-switch). Letters from A to Z had to be clicked alphabetically. 3. Third section, consecutively switching between numbers and letters in ascending order (i.e., 1-A-2-B-3-C…13-M). The target turned red if the answer was incorrect or green if the answer was correct. (B). Visual-spatial memory measured by the Corsi block-tapping task. Nine blue squares appearing as stimuli on the screen changed the color in a spatial random order. Three to six block sequences were displayed and had to be repeated in the same order. (C). Working memory updating measured by a 2-back task. Fruits and vegetables were displayed on a computer screen. A predefined key had to be pressed when the current image was the same as the image two trials back. (D). Inhibitory control measured by flanker task. Directional response to the stimuli: congruent flankers and incongruent flankers were needed by pressing a defined computer key.