ABSTRACT
Exercise performance may be improved by listening to high-tempo and motivational music prior to exercise. However, the effects of the combination of “tempo” and “motivational factors other than tempo” of music on exercise performance have not been examined in detail. We examined whether listening to music before exercise affects repetitive sprint performance and psychological responses in healthy young men. Twenty-one healthy men performed two consecutive sets of 20-second sprint cycling with a 120-second rest period between sets. Five types of music were used during the warm-up and rest periods: no music (Con), high-tempo music that subjects judged to be motivating (MH, 130~140 bpm), high-tempo music that subjects judged to be unmotivating (UMH, 130~140 bpm), low-tempo music that subjects judged to be motivating (ML, 70~80 bpm), and low-tempo music that judged to be unmotivating (UML, 70~80 bpm). Motivation, pleasure-displeasure and arousal-sleepiness, and rate of perceived exertion were investigated using a questionnaire. The maximum power per body weight during sprint cycling was significantly higher in ML than in Con, and MH tended to be higher than in Con. Motivation increased significantly from “After Warm-up” to “After Recovery” for MH and ML, but did not change significantly for Con, UMH, and UML. These results suggest that listening to motivational music, regardless of tempo, improves the maximum power of sprint cycling.
ABSTRACT
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.
ABSTRACT
Recently, a standing desk is being installed as a behavior change strategy to reduce sitting time in the workplace. However, the standing posture has been suggested to decrease forehead oxygenated hemoglobin (oxy-Hb), which might impair task performances. Therefore, we examined whether prolonged standing impairs speed and accuracy of computer subtraction task associated with a decrease in forehead oxy-Hb. Nine healthy young males completed 4 × 15-min computer tasks under two conditions, i.e., sitting and standing. In the computer tasks, all subjects were required to subtract a two-digit number from a four digit number written on the paper and to input the answer to the answer colomn on the computer. Task performances were evaluated as the number of achievements and accuracy rate every 15 minutes. Moreover, oxy-Hb and deoxygenated-hemoglobin (deoxy-Hb) in the site of left forehead area and lower limb were monitored throughout the experimental period by near-infrared spectroscopy. Forehead oxy-Hb was significantly associated with the number of achievements during computer tasks (p < 0.001). In addition, forehead oxy-Hb and task performances did not differ between sitting and standing. The number of achievements of subtraction task under standing condition was significantly decreased as time proceeds. Our results demonstrate that prolonged standing might impair computer subtraction task performances irrespective of the change in forehead oxy-Hb.
ABSTRACT
The effects of physical activity (PA) on bone mass gained during growth in Japanese are not well understood. The purpose of this study was to examine whether changes in PA affected bone mass gained by Japanese schoolchildren, as measured by calcaneus quantitative ultrasound (QUS). Three hundred and seven children aged 9–13 years participated in the study and were followed for a 2-year period. The stiffness index (Stiffness) of the calcaneus was measured by QUS, and PA evaluated by a questionnaire. Participants were divided into two groups according to PA: high (≥ 7 hours/week, H) or low (< 7 hours/week, L). Participants were also divided into four groups according to their 2-year change in PA: consistently high (HH), consistently low (LL), changed from high to low (HL), and changed from low to high (LH). Analysis of covariance was used to compare adjusted Stiffness across all four groups. The adjusted 2-year changes in Stiffness ranked in decreasing order among girls: HH (20.8 %), HL (17.6 %), LH (14.3 %), and LL (12.2 %), respectively (trend test, P = 0.027). This trend was not observed among boys. These results suggest that changes in PA significantly affected bone mass gain among peripubertal girls, and that a continuing PA of more than 7 hours a week (approximately ≥ 60 min/day) from a young age is effective in increasing peak bone mass. However, given the limitations of this study, further robust studies which recruit representative samples and consistently employ validated measurement instruments are needed.
ABSTRACT
In recent years, physical inactivity among children or adolescents has been a major public health concern. Although a number of studies have examined the effect of physical inactivity on depressive symptoms in adults, only few studies have examined this effect on children. Therefore, the purpose of this study was to examine the effect of physical activity on the development of depressive symptoms in children by using longitudinal data. The study participants were students in grades 4 to 8 in the Koshu City. Their physical activity and depressive symptoms were examined in 2008 by a questionnaire. One year later, their depressive symptoms were examined again. Students who had depressive symptoms at the baseline were excluded. Physical activity at the baseline was categorized into 3 groups as independent variables. The development of depressive symptoms was used as the dependent variable. Multivariate logistic regression analyses were performed to examine the relationship. At the baseline, 1532 students completed the questionnaire. Of them, 1379 students (727 boys and 652 girls) did not have depressive symptoms. One year later, 1319 students (95.6%) completed the questionnaires on depressive symptoms. Of them, 41 (6.0%) boys and 68 (10.6%) girls had developed depressive symptoms during the study period. High physical activity was significantly associated with decreased incidence of depressive symptoms compared to low physical activity only in boys (odds ratio: 0.37, 95% confidence interval: 0.12-0.95). Our results suggest that high physical activity significantly affects the depressive symptoms in boys.
ABSTRACT
The purpose of this study was to investigate the effect of attenuation of exercise-induced oxidative stress by antioxidant administration on brain-derived neurotrophic factor (BDNF) expression in the rat hippocampus. Wistar rats were assigned to four groups: non-exercise (Cont), exercise (Ex), or the combination of exercise with antioxidant administration (small dose: SP, large dose: LP) group. Exercise groups were subjected to treadmill running for 10 consecutive days. The exercise load increased gradually by 5 m/min per day for the first 5 days (10 m/min-30 m/min), and maintained at 30 m/min for the last 5 days. In addition, SP and LP were injected with N-tert butyl-a-phenyl nitrone (PBN) 1h prior to exercise. High-intensity exercise resulted in increased hippocampal 4-hydroxy-2-nonenal (4-HNE) contents compared with Cont. But this elevation was completely suppressed by a large dose of PBN. In Ex and SP, serum total antioxidative power were significantly decreased compared with Cont, whereas no changes were observed in LP. There was a significant negative correlation between hippocampal 4-HNE contents and serum total antioxidative power in SP and LP, suggesting the hypothesis that exercise-induced reduction in total antioxidant power might lead hippocampal 4-HNE accumulation. Furthermore, there was a significant increase of hippocampal BDNF level in LP compared with Cont and Ex. These findings indicate that an increase of oxidative stress might not have a beneficial effect on hippocampal BDNF expression. Our results of this study also suggest that attenuation of exercise-induced oxidative stress by some antioxidants contributes to BDNF expression in the hippocampus.
ABSTRACT
The purpose of this study was to investigate heme oxygenase-1 (HO-1) mRNA expression and bilirubin concentration alteration in humans exposed to acute hypoxia. Fourteen healthy adult males were randomly assigned to a sea level group and a hypoxia group, and then exposed to normoxia (400 m, 20.0 %O<sub>2</sub>) and hypoxia (3,000 m, 14.5 %O<sub>2</sub>) respectively, in a hypoxic chamber for 3 hours. SpO<sub>2</sub> during hypoxia were significantly lower than those at sea level (P＜0.05). Indirect bilirubin levels after hypoxia were significantly higher than those at sea level (P＜0.05). However, HO-1 mRNA expression was unaltered by hypoxia. In conclusion, our data indicate that an acute exposure to hypoxia at resting state for 3 hours might lead to antioxidative cytoprotective response without any increase in HO-1 gene expression.
ABSTRACT
The college years are an opportune timepoint of intervention in the primary prevention of osteoporosis. However, the effects of anthropometrical measures and lifestyle-related factors on the changes in bone mass during college years are unclear. The purpose of this study was thus to identify the determinants of the changes in calcaneal quantitative ultrasound (QUS) bone parameters (stiffness index: SI, speed of sound: SOS, broadband ultrasound attenuation: BUA) over 2 years in healthy Japanese college women (n=128). Correlation analysis revealed several significant relationships between the change rates in QUS parameters and anthropometry. Particularly, the changes in SI and BUA are highly correlated with the 2-year change in lean body mass (LBM). The subsequent multiple liner regression analysis also supported that the change in LBM was the significant predictor for the incremental rate of SI and BUA. All subjects then categorized into some grades, concerning about following lifestyle-related and physical variables during the last 2 years, living condition, sleeping time, alcohol consumption, smoking, meal skipping, dairy foods intake, instant foods intake, regular physical activity, regularity of menstruation, history of fracture, and history of dieting to reduce body weight. The incremental rates of all QUS parameters (i. e., SI, SOS, BUA) were positively associated with participation in regular physical activity. In addition, women who have continuously participated in regular physical activity from high school to college showed significant increases in SI and SOS compared with those who are not physically active or whose level of physical activity decline during college years. In conclusion, our study indicates that changes in QUS parameters in college-aged women were influenced by changes in anthropometric measures, especially LBM. It might suggest the importance of participation in regular physical activity to increase skeletal muscle mass. Our results also support the view that college women should maintain or increase regular physical activity before and after entering the college to maximize peak bone mass or lessen the age-related loss in bone mass in adulthood.
ABSTRACT
The purpose of this study was to examine the effects of anthropometric measures, including body height, body weight, body mass index (BMI), fat mass (FM), and lean body mass (LBM), on quantitative ultrasound (QUS) parameters of calcaneus in 358 Japanese university women. Ultrasonic bone densitometer (Achilles, Lunar corp.) was utilized to measure broadband ultrasound attenuation (BUA), speed of sound (SOS), and stiffness index (SI) of the right calcaneus. The average of SI in this study showed a slight lower value (84, 3±12.1, mean±SD) compared with that in age-matched university women as previously reported. The contradictive finding may suggest the need for a large-scale further investigation on SI in young women. Correlation analysis revealed that both BUA and SI are significantly correlated with all anthropometric measures. However SOS had only weak correlation with LBM. In consideration of the high colinearities of body weight and BMI with FM and LBM, the multiple liner regression analysis was conducted with BUA, SOS, and SI as dependent variables. Body height, FM, and LBM were then entered to a forward stepwise regression model. The analysis proved that the significant predictor of BUA, SOS, and SI is LBM. It also suggested BUA to be stronger correlated with LBM than the other QUS parameters, SOS and SI. In conclusion, our re sults support the view that QUS parameters appear to be influenced by anthropometric measures, especially by LBM in Japanese university women. It is conceivable that an increase in skeletal mus cle mass chiefly induced by physical exercise contributes to the improvement of bone mass as measured by QUS in young women.