Fundamental movement skills in preschoolers before and during the COVID-19 pandemic in Japan: a serial cross-sectional study.

BACKGROUND: Physical inactivity during the coronavirus disease 2019 (COVID-19) pandemic may have hindered the development of fundamental movement skills in preschoolers. This serial cross-sectional study compared fundamental movement skills by age group before and during the COVID-19 pandemic (2019-2020), among Japanese preschoolers aged 3-5 years. METHODS: Of the 22 preschools within Unnan City, Shimane Prefecture, Japan, 21 (95.5%) and 17 (77.3%) participated in the 2019 and 2020 surveys, respectively. We analyzed 608 and 517 preschoolers in both surveys. Fundamental movement skills were objectively assessed with a 25 m run, standing long jump, and softball throw, based on the Japanese physical activity guidelines for preschoolers. Mann-Whitney U tests were used to compare the fundamental movement skills data between periods. RESULTS: For the 25 m run, participants aged 5 years were faster before than during the pandemic (p = 0.018), while participants aged 3 and 4 years showed no significant differences. Participants aged 3-5 years showed no significant differences before and during the pandemic for the standing long jump (p ≥ 0.072). For the softball throw, all grades scored higher before than during the pandemic (p < 0.001). CONCLUSIONS: These findings suggest that the COVID-19 pandemic impeded the development of fundamental motor skills, especially for object control skills. This highlights the need for interventions aimed at developing fundamental motor skills in preschoolers during and after the pandemic.

Prevalence and Correlates of Physical Activity Among Children and Adolescents: A Cross-Sectional Population-Based Study of a Rural City in Japan.

BACKGROUND: Although moderate-to-vigorous physical activity (MVPA) has multiple health benefits, current participation in recommended MVPA level and its determinants among Japanese children and adolescents remain unclear. Therefore, this cross-sectional study investigated the prevalence of meeting recommended MVPA level and its correlates among Japanese children and adolescents. METHODS: Using the Japanese version of the World Health Organization (WHO) Health Behaviour in School-aged Children survey questionnaire, we confirmed the prevalence of meeting recommended MVPA level in all primary schools (PS) and junior high schools (JHS) in Unnan City, Japan. We evaluated its association with school grade, gender, body weight status, screen time, consumption of breakfast, physical activity (PA) preference, and population density using Poisson regression. RESULTS: We found that 20.1% of the 1,794 students (9-15 years old) met the WHO recommendation. Meeting recommended MVPA level was significantly associated with being in the sixth grade of PS (prevalence ratio [PR] 0.57; 95% confidence interval [CI], 0.39-0.84) and first (PR 1.52; 95% CI, 1.16-1.99), second (PR 1.45; 95% CI, 1.10-1.90), and third grade of JHS (PR 0.40; 95% CI, 0.26-0.62) (vs fourth grade of PS); being a boy (PR 1.33; 95% CI, 1.12-1.59) (vs girl); liking PA (PR 3.72; 95% CI, 2.22-6.22) (vs dislike); and belonging to a medium-population-density (PR 0.73; 95% CI, 0.61-0.88) or low-population-density area (PR 0.67; 95% CI, 0.48-0.94) (vs high-population-density area). CONCLUSIONS: About 20% of Japanese children and adolescents engaged in the recommended MVPA level. MVPA was associated with grade, gender, preference for PA, and population density.

The Motor Engram of Functional Connectivity Generated by Acute Whole-Body Dynamic Balance Training.

PURPOSE: Whole-body dynamic balance is necessary for both athletic activities and activities of daily living. This study aimed to investigate the effect of acute dynamic balance training on neural networks. METHODS: We evaluated resting-state functional connectivity (rs-FC), white matter fiber density, fiber-bundle cross-section, and gray matter volume in 28 healthy young adults (14 women) before and after 30 min of slackline training using a randomized, counterbalanced crossover design. RESULTS: The rs-FC between the left lateral prefrontal cortex (PFC) and the foot area of the primary sensorimotor (SM1) cortex increased significantly after slackline training compared with that after a control condition involving ergometer-based aerobic exercise. In addition, changes in rs-FC between the left lateral PFC and the primary sensorimotor were correlated with performance changes after training (i.e., offline process) rather than online learning. We also observed a main effect of time between the hippocampus and the cingulate cortex, including the anterior areas, and between the bilateral lateral PFC. Although we observed no structural changes, fiber density in the commissural fiber pathway before the first balance assessment was correlated with initial balance capability. CONCLUSIONS: Our findings demonstrate that acute whole-body dynamic balance training alters specific rs-FC, and that this change is associated with performance changes after training. In addition, rs-FC changes in cognitive regions were modulated by both acute dynamic balance training and aerobic exercise. These findings have the potential to influence various fields (e.g., sports neuroscience, neurorehabilitation) and may aid in the development of methods that can improve motor and cognitive performance.

Movement Coordination during Forward and Backward Rope Jumping: A Relative Phase Study.

Rope jumping is a popular training method in athletic programs, fitness, and physical education. Forward and backward rope jumping has been used for evaluating athlete's performance. Both of these two jumps require coordination in the upper and lower limbs. However, no study has focused on movement coordination during forward and backward rope jumping. Relative phase (RP) analysis was widely known as an innovative method for evaluating human movement coordination. Thus we aimed to investigate the movement coordination during forward and backward rope jumping by using RP analysis. 78 elementary and junior high school students participated in this study. 30 seconds rope jumping was recorded for both forward and backward by using iPhone video. Pose estimation software was used for jump motion tacking. Movement coordination was analyzed through RP analysis, absolute maximum value, mean absolute RP, and deviation phase were calculated for evaluating movement coordination, the trend of in or out-of-phase, as well as movement stability. As a result, 3994 forward and 3961 backward jumps were analyzed. There was a significant difference in movement coordination between forward and backward rope jumping. Compared to forward, backward jumps showed worse movement coordination, a trend to be out-of-phase, and less stability. It was the first time that movement coordination during rope jumping was studied. We considered that further research on coordination during rope jumping can provide new insight into athlete performance management, fitness guidance, and physical education.

Effects of High Intensity Interval Training on Executive Function in Children Aged 8-12 Years.

This study investigated the effects of a high intensity interval training (HIIT) program on both physical fitness and executive functions in children. Fifty-six children aged 8-12 years participated in this study, and were divided into a HIIT group and a control group. The HIIT group performed three sessions of the 8- to 10-min HIIT program per week for 4 weeks. Before and after the intervention, 20-m shuttle runs, sit-ups, and standing long jumps were assessed as test of physical fitness. In addition, the executive function was assessed using the digit span forward (DSF) test, digit span backward (DSB) test, and Tower of Hanoi test. Only the HIIT group experienced significant improvement when completing the 20-m shuttle run (p = 0.042) and sit-ups (p < 0.001). Regarding executive function, the number of correct answers in DSB test significantly increased only in the HIIT group (p = 0.003). However, the standing long jump, DSF, and the Tower of Hanoi test performance did not change after intervention. The findings of the present study suggest that HIIT has positive effects on a core executive function such as working memory in addition to components of the physical fitness such as cardiorespiratory endurance and muscular endurance.