Akari Kamimura

Relative Age Effect on Psychological Factors Related to Sports Participation Among Japanese Elementary School Children

Children born soon after the selection period’s cut-off date (early-born children) may benefit by up to a full year in physical and psychological development compared with children born just before the cut-off date (late-born children). This phenomenon is called the “relative age effect” (RAE). RAE is defined as the consequence of age differences between individuals within the same cohort, either in school or on sports teams. We examined the RAE on physical activity enjoyment, physical activity competence, attitude toward physical activities, attitude toward physical education, and frequency of participation in physical activities among Japanese elementary school children. Data were collected from 961 Japanese elementary school children (478 male, 483 female). The results showed that early-born children scored higher than late-born children did in the above-mentioned variables. This indicated that the RAE exists for psychological factors related to sports participation among Japanese elementary school children.

The Impact of Physical Activity Enjoyment on Motor Ability

This study aimed to examine the impact of physical activity enjoyment on the motor ability of school-age children. We collected data from 351 elementary school students (180 boys and 171 girls; Mage = 8.78, standard deviation = 1.85) from public elementary schools in Japan. We investigated individual profiles (sex, age, birth date, and school year), children’s physical size (height, weight, and Rohrer index), children’s motor ability (performance during a 50-m sprint, standing broad jump, and throwing a soft ball), and enjoyment of physical activity using the Physical Activity Enjoyment Scale (PACES). We assessed the effect of physical activity enjoyment (independent variable) on motor ability (dependent variable) using binomial logistic regression analysis. An examination of confounders (chi-square test) indicated that weight and Rohrer index were the influential factors in the 50-m sprint (ps < .05). Therefore, the adjusted ORs for these factors were calculated using logistic regression analysis. The adjusted analysis results indicated that enjoyment (PACES score ≥ 4.00) is a promoting factor for motor ability.

Impact of Emotion Regulation on Mental Health of Japanese University Athletes

Athletes’ mental health is a great concern for coaches, supporters, and researchers in the field of sports science. To prevent mental health problems in athletes, emotion regulation strategies are considered effective for coping with stressors. Emotion regulation is defined as the regulation of thoughts or behaviors that influence the emotions. Emotions may influence not only the mental health but also performance in competitive sports. Therefore, we examined the impact of emotion regulation on the mental health of Japanese university athletes. We collected data from 927 Japanese university athletes (535 male and 392 female). We collected information on athletes’ demographics, emotion regulation (Emotion Regulation Questionnaire: ERQ), and mental health (Self-report Depression Scale: SDS, and General Health Questionnaire-30; GHQ-30). A regression analysis showed that reappraisal had a significant negative effect on SDS (β = .−44, p < .001, R2 = .19) and GHQ-30 scores (β = .−26, p < .001, R2 = .08) but suppression did not affect either of them. This indicates that athletes using reappraisal have a good mental health, thereby suggesting that emotion regulation may contribute to the maintenance of athletes’ mental health. Thus, we concluded that emotion regulation has an impact on the mental health of Japanese university athletes. Sports coaches and supporters of athletes should pay substantial attention to athletes’ emotion regulation strategies to maintain their mental health and enhance their performance.

The Effect of Awareness of Physical Activity on the Characteristics of Motor Ability Among Five-Year-Old Children

We examined the relationship between the types of awareness about physical activity and motor ability among Japanese 5-year-old children. Data were collected from 169 five-year-old children (85 boys and 84 girls). We found that children’s awareness of their own physical activity (liking, enjoyment, and the confidence in physical activity as their physical competence) and actual motor ability (20-m sprint, standing broad jump, throwing a tennis ball) were weakly associated. Moreover, in classifying children’s awareness of physical activity, we extracted four clusters of awareness characteristics. Notably, we found that some children with negative awareness did not have poor motor ability, whereas some children with positive awareness did not have good motor ability. Understanding these phenomena would be essential for building exciting environments that help all children view physical activity as play.

Effect of Relative Age on Physical Size and Motor Ability Among Japanese Elementary Schoolchildren

A child born soon after the designated cut-off date (“early-born”) may benefit by up to a full year in physical and psychological development, unlike one born just before the cut-off date (“late-born”). This phenomenon—called the “relative age effect”—causes inequalities in education and impacts the psychological aspects of children’s sports participation. However, its influence on physical aspects has not been clarified. Therefore, we examined its impact on physical size and motor ability among Japanese elementary schoolchildren (384 males and 360 females). We collected demographic data and measured physical size and motor abilities. Analysis of covariance showed that early-born children scored significantly higher than late-born children across variables, indicating the effect of relative age on physical aspects of sports participation and the possible advantage of early-born over late-born children in sports achievement. We propose the need for acknowledging this phenomenon in educational settings among teachers and coaches.