Intermittent exercise performance in a hot environment is lower than in temperate conditions. Cooling strategies at rest are important; however, the appropriate cooling temperature is not clear. The purpose of this study was to investigate the effect of temperature for cooling leg during half-time (HT) on intermittent exercise performance. Eleven men performed two pre-tests and three experimental trials of a 2 × 30 min intermittent exercise protocol in the heat (33°C; 50% relative humidity). During HT, three experimental conditions were set: no cooling (CON), cooling at the thigh using 12°C ice packs (COOL), and cooling at the thigh using 0°C ice packs (ICE) for 15 min. During the 2nd half, which consisted of 5 s maximal power pedaling every minute separated by 50 s of unloaded pedaling (80 rpm) and rest (5 s), the subjects repeated 2 × 15 sets of the intermittent exercise protocol. The peak power output under the COOL condition (694 ± 80 W) was significantly higher than that of the CON (653 ± 84 W). Thigh skin and deep temperatures showed a significant difference between each condition. In the COOL, thermal sensation was significantly lower, and thermal comfort was significantly higher. In a protocol that simulates intermittent athletic competitions such as soccer in a hot environment, using ice packs at 12°C to cool the thigh during HT lowered thigh skin and deep temperatures and improved heat perception and intermittent exercise performance. This cooling strategy is practical, suggesting that it would be effective for actual competitive situations.

We examined the relationship between masticatory ability and bone mineral density (BMD) and the role of muscle strength in those relationships in 156 female university students. Masticatory ability was assessed using a color-changeable chewing gum method. The BMD of the calcaneus was measured using quantitative ultrasonography and represented by a T-score, the standard deviation (SD) from the mean BMD of young adults. Body composition, grip strength, physical activity level, and daily nutrient intake were also assessed. Osteopenia, defined as the T-score < ‒1.0 SD, was present in 43 participants (27.6%). There was no significant relationship between masticatory ability (ΔE) and T-score in all participants. In participants with normal BMD (T-score ≧ ‒1.0 SD: the normal BMD group), masticatory ability significantly correlated to BMD (r = 0.289, p = 0.002). There was significant correlation between ΔE and grip strength neither in all participants nor in either group, although the grip strength in the normal BMD group was greater than that in the participants with osteopenia (the low BMD group) (p = 0.039). Physical activity level was positively correlated to the total daily energy intake (r = 0.193, p = 0.041) only in the normal BMD group. The present results suggest that masticatory ability is associated with BMD in young females with normal BMD, but the role of muscle strength in those relationships remains unclear. Meanwhile, there was no relationship between masticatory ability and BMD in young individuals with lower BMD.

This study examined the relationship between meeting the World Health Organization’s (WHO) 24-Hour Movement Guidelines for the Early Years and motor skills and cognitive function in preschool children. Participants were 4-year-old boys and girls in urban and rural areas (n=69). Physical activity was measured using a triaxial accelerometer (ActiGraph GT3X). Screen time and sleep duration were assessed via self-report by guardians. Meeting the 24-h movement guidelines was defined as: 10 to 13 h/night and nap of sleep, ≤1 h/day of sedentary screen time, and at least 180 min/day more than 1.5 METs. Motor skills were evaluated by the Ages & Stages Questionnaires, Third Edition (ASQ-3). Executive functions (shifting, visual-spatial working memory and inhibition) were evaluated by the Early Years Toolbox (Japanese translation). The prevalence of children meeting all three recommendations was 7.2% and 7.2% met none of the three recommendations. Children meeting physical activity recommendation had a better inhibition score compared to children meeting none of the recommendation (p=0.005). While, children not meeting the sleep recommendation had a better inhibition score compared to children meeting of the recommendation (p=0.042). In conclusion, meeting the physical activity or sleep recommendations were positively or negatively associated with the inhibition score. On the other hand, meeting none of the sedentary behaviour and the 3 recommendations was not associated with motor skills or cognitive function.

Walking football was born in United Kingdom around 2011, that is forbidden to running. In recent years, walking football has become increasingly popular as a sport that diverse people can enjoy together. However, it is not clarified exercise intensity and how they feel after playing walking football. We aimed to determine the intensity when playing walking football and investigated how mood change. Twenty-six men and women (18 males, 8 females) out of those who participated in walking football event agreed to the present study. Heart rate (HR) was measured using wearable device with photoplethysmography when playing walking football. Metabolic equivalents (METs) was assessed using a triaxial accelerometer worn on the waist. McGill pain questionnaire was used to assess pain sites and number. To assess change in mood, short version of physical activity enjoyment scale (sPACES) was used before and after playing walking football. Borg scale was measured before and after walking football. The HR and METs were respectively as follows; male, 111.9 ± 11.4 bpm and 4.3 ± 0.6METs; female, 118.6 ± 16.2 bpm and 4.8 ± 0.7METs. There was no significant difference between men and women in both HR and METs during walking football. The sPACES was indicated significantly positive changes in mood, and Borg scale was significantly increased after playing walking football, without increasing acute or chronic pain. The walking football is safe and moderate-intensity sports and induce positive changes in mood.

Circadian rhythms have been shown to regulate several physiological functions including body temperature, sleep/wake cycle, physical activity, and cognition. These functions are controlled by circadian clock genes, and the circadian clock system in the body is classified into two clocks which are the central clock in the suprachiasmatic nucleus (SCN) of the hypothalamus and peripheral clocks in peripheral tissues such as the liver and skeletal muscle. Therefore, many researchers are conducting basic and applied research on the relationship between circadian rhythm in peripheral tissues and physiological functions including sports performance and effects of acute exercise and exercise training. On the other hand, it has been shown that abnormal circadian rhythms and disturbance of circadian rhythms can lead to the development of several diseases such as diabetes, cancer, sarcopenia, depression, and dementia. Thus, it is also important to regulate individual circadian rhythm by considering for timing of exercise and daily physical activity. Exercise and physical activity are found to have an influence on circadian rhythms regulation (Chrono-exercise) and accumulate evidences between timing of exercise and health outcomes. This review aims to introduce evidence for chrono-exercise and suggests the importance for considering the timing of exercise and physical activity.