ABSTRACT
This report provides an overview of the effectiveness of objectively measured physical activity, sports participation, and outdoor play on outcomes related to mental health and social skills in children and adolescents. Findings based on observation studies of longitudinal and cross-sectional design are inconsistent. On the other hand, several intervention studies with high intensity exercise programs indicated that intensity and amount of physical activity might provide a short-term benefit against depressive symptoms and anxiety. However, there are reports that psychosocial approaches confer effects similar to exercise programs. The effects of participation in organized sports clubs on mental health conditions such as depression, anxiety, self-esteem, self-efficacy, health-related quality of life, social skills (e.g., relationship skills), and coping ability were diverse. Notably, there could be unfavorable relationships in athletes exhibiting a higher performance. Meanwhile, participation in sports could represent a predictor of escalation in alcohol use as evidenced by longitudinal observation studies in adolescent, although there could also be effectiveness in terms of preventing use of illicit drugs. Lastly, active outdoor play under natural conditions without supervision also represented an effective approach to promote mental health (e.g., reducing depressive symptoms and building social skills such as self-regulation and coping skills in the face of difficult human relationships). We recognize that not only sports participation but also outdoor play under abundant nature environment could represent a significant physical activity to maintain mental and social health from childhood to adolescence.
ABSTRACT
<p>The International Physical Activity Questionnaire (IPAQ) is a self-reported questionnaire for assessment of physical activity and has been validated in many countries among adults. However, there are few studies about the validity of IPAQ for children. The purpose of this study was to investigate the validity of moderate to vigorous physical activity according to the modified version the IPAQ for Japanese Early Adolescents (IPAQ-JEA). Ninety-two adolescents aged 10-13 years participated in this study. The validity of the IPAQ-JEA criteria was tested using an activity monitor (Active style Pro, HJA-350IT; ASP). Daily physical activity was continuously monitored for one week by ASP. The participants were asked to complete the IPAQ-JEA after wearing the ASP. The epoch length of ASP was set at 1-min in this study (ASP<sub>1-min</sub>). According to the minute by minute METs values, time spent on moderate intensity physical activity (MPA, 3 to 6 METs), vigorous intensity PA (VPA, > 6 METs), and moderate to vigorous intensity PA (MVPA, > 3 METs) was calculated. In addition, we also calculated bout physical activity maintained for 10 minutes or longer (ASP<sub>bout</sub>). Weekly time spent on MVPA assessed by IPAQ-JEA (MVPA_IPAQ-JEA) was significantly correlated with that assessed by ASP<sub>bout</sub> (MVPA_ASP<sub>bout</sub>) (ρ=0.359, p<0.01) and ASP<sub>1-min</sub> (MVPA_ASP<sub>1-min</sub>) (ρ=0.399, p<0.01). However, MVPA_IPAQ-JEA was significantly higher than that of MVPA_ASP<sub>bout</sub> and MVPA_ASP<sub>1-min</sub> (p<0.001). Although time spent on VPA assessed by IPAQ-JEA (VPA_IPAQ-JEA) was also significantly correlated with that assessed by ASP<sub>bout</sub> (VPA_ASP<sub>bout</sub>) (ρ=254, p<0.05) and ASP<sub>1-min</sub> (VPA_ASP<sub>1-min</sub>) (ρ=438, p<0.01), time spent on VPA_IPAQ-JEA was significantly higher than that for VPA_ASP<sub>bout</sub> and VPA_ASP<sub>1-min</sub> (p<0.001). These results support the use of the IPAQ-JEA as a relative measure of physical activity among 10-13-year-old children.</p>
ABSTRACT
<p>The purpose of this study was to assess the effectiveness of 12 months of walking exercise interventions to improve sleep quality in older adults. One-hundred ninety healthy older adults were divided into a 12 months walking exercise group (n = 120) and a control group (n = 70). Furthermore, to investigate whether the difference in step count changes affected sleep quality, the walking exercise group was sub-divided into a high-walking exercise group (n = 60) and a low-walking exercise group (n = 60) according to the median number of percent change of steps. The main outcome measures were daytime sleepiness (Epworth Sleepiness Scale: ESS) and sleep quality (Pittsburgh Sleep Quality Index: PSQI) questionnaires. The high-walking exercise group showed significant improvements in ESS (p < 0.01), PSQI global score (p < 0.01), subjective sleep quality (p < 0.05), sleep disturbance (p < 0.05) compared to the baseline scores. In the high-walking exercise group, the result of average step counts per day was significantly increased compared to the baseline (p < 0.01). These results suggest that the 12 months walking exercise intervention was an effective approach to improve sleep quality in older adults who maintained the increase in step counts during the intervention period.</p>
ABSTRACT
The purpose of the present investigation was to examine the relationships between the exercise history and the bone mineral density (BMD) and bone mineral content (BMC) in female Japanese young adults using dual X-ray absorptiometry (DXA). One-hundred twenty females, aged between 18 to 28 years, participated in the present investigation. The BMD at the lumbar spine (L-BMD), whole body BMD and BMC (WB-BMD and WB-BMC), lean body mass (LBM) and fat mass (FM) were measured by DXA. Using a self-administrered questionnaire, the exercise habits during preschool (4-6 years), primary school (7-12 years), junior high school (13-15 years), high school (16-18 years), and the current habits (>18 years) were eveluated. The L-BMD, WB-BMD and WB-BMC were significantly higher in the subjects with exercise habits during both the period of <18 years and >18 years compared with those in the subjects without an exercise history during all periods (p<0.05). In a separate analysis with the data stratified by the school age, the subjects with an exercise history during primary school, junior high school, or high school had significantly higher BMD and BMC values compared with the non-exercisers (each, p<0.05). In contrast, the BMD and BMC did not differ significantly according to either the exercise history during pre-school nor the current exercise status. A multiple stepwise regression analysis revealed that the body weight, LBM, FM, age of menarche, and exercise habits during high school were significant determinants of the L-BMD, WB-BMD and WB-BMC (p<0.001). The results of the present investigation show that both the exercise history during school age and the current exercise habits affect the BMD and BMC in young adults. In particular, high school females should be encouraged to participate in the regular exercise to increase their bone health. Future studies will be needed to confirm the targeted age-group(s) for participation in sports/exercise for the improvement of bone health, including an analysis of the type and intensity of exercise/sports.
ABSTRACT
The purpose of this study was to examine the relationships between patterns of daily physical activities measured by accelerometer and physical activity level (PAL) in children. Firstly, activity intensities during incremental exercise were measured using a tri-axial accelerometer (HJA-350IT) in twenty one children aged 10.6 ± 0.9 years. As a result of receiver-operating characteristic curve analysis, the cut-off value for discrimination between walking and running activity was set at 7.2 METs of HJA-350IT. Secondly, total energy expenditure (TEE) in daily life was measured by doubly labeled water method, and durations of lifestyle, walking, and running activities were measured by the accelerometer in 6<sup>th</sup> grade elementary school children (11 boys and 10 girls). TEE and physical activity level (PAL) were 2,021 ± 343 kcal/day and 1.56 ± 0.17, respectively. The average durations of lifestyle, walking and running activities were 188 ± 30 min/day (50.6 ± 6.0 %), 171±28 min/day (45.9 ± 5.0 %) and 13.3 ± 7.6 min/day (3.5 ± 1.8 %), respectively. The proportion of the duration of running activity was positively correlated with PAL (r = 0.615, p < 0.01), and the proportion of the duration of lifestyle activity was negatively correlated with PAL (r = -0.439, p < 0.05). There was no relationship between the proportion of the duration of walking activity and PAL (r = 0.300, n.s.). These results suggest that running activity is important to increase PAL more than ever in primary school children.
ABSTRACT
The relationships between physical activity and childhood body size, low physical fitness epidemic are still unclear. The purpose of this study was to examine the relationship between energy expenditure estimated by doubly labeled water (DLW) method and body fatness, physical fitness in children, and the relationship between physical activity levels and percent time spent in activities. 30 healthy Japanese children (20 boys and 10 girls) participated in this study. The total energy expenditure (TEE) and % body fat were measured by the DLW method over a 6-day period. The physical activity-related energy expenditure (PAEE) was calculated as (TEE × 0.90) – basal metabolic rate (BMR). The physical activity level (PAL) was also calculated as TEE/BMR. The physical fitness tests (8 items) were applied to evaluate fitness, and scores of each test were calculated as overall physical fitness score. The TEE was 2009.8 ± 272.6 kcal/day, the PAEE was 558.4 ± 206.1 kcal/day and the PAL was 1.61 ± 0.18. TEE per weight and PAEE per weight (PAEE/wt) was significantly negatively correlated with % body fat (r = - 0.626; r = - 0.400, respectively). These results suggest that increasing energy expenditure is important for achieving adequate body size. The PAEE/wt was most strongly correlated with physical fitness score (r = 0.680). The PAL was associated with percent time spent of inactivity ( r = -0.506), light-moderate activity ( r = 0.450) and vigorous activity ( r = 0.545). It was suggested that physically active lifestyle would be necessary for childhood health.
ABSTRACT
We performed exercise intervention for 12 weeks in young females (22.3±2.5 yrs ; mean±SD) with a %fat value of 30% or more (dual energy X-ray absorptiometry : DXA) despite a body mass index (BMI) of less than 25 kg/m<sup>2</sup>, which indicates hidden obesity, and the following results were obtained.The intensity of exercise was established as the double product break point calculated from heart rate and systolic blood pressure, and the subjects were instructed to exercise for 30 minutes or more for 3 or more times a week. Six weeks after exercise intervention, the BMI, body fat level, and plasma glucose level were lower than those before exercise intervention, and the %fat value was lower 12 weeks after intervention. Furthermore, cardiac autonomic function (CAF) was negatively correlated with changes in Total power and changes in fat (kg), suggesting that exercise-related improvement in CAF is involved in a decrease in %fat.
ABSTRACT
PURPOSE : The purpose of the present study was to clarify the effect of static stretching on muscular performance with concentric isotonic muscle actions under various loads.METHODS : Concentric isotonic leg extension power outputs were assessed in 12 healthy male subjects after two types of pre-treatment. The pre-treatments included 1) static stretching (SS) treatment performing static stretching of leg extensors, and 2) non-stretching (NS) treatment by resting in a sitting position. Loads during the assessment of the power output were set to 5%, 30% and 60% of the maximum voluntary contractile (MVC) torque with isometric leg extension in each subject.RESULTS : The peak power output following the SS treatment was significantly (P<0.05) lower than that following the NS treatment under each load.CONCLUSION : The present study demonstrated that static stretching significantly reduces power output with concentric isotonic muscle actions under various loads. This result suggests that static stretching decreases power performance.
ABSTRACT
Double product (DP, heart rate × systolic blood pressure) during an incremental exercise test has been known to start to increase steeply at a workload, i. e. double product break point (DPBP), which corresponds to the blood lactate threshold. The study was to investigate the relationship between DP transition and ST segment depression in electrocardiogram during exercise. Thirty-one patients of angina pectoris of effort and 140 elderly persons performed a continuous incremental exercise test using a stationary bicycle ergometer. During the entire test, HR and blood pressure were measured every 15 seconds and an electrocardiogram was recorded continuously. DPBP was then calculated. In ten of the 31 patients, ST level depression above -0.1 mV with a typical ischemic form in lead V 5 was observed during the test. However, workload at the DPBP was significantly lower than that of the ischemic threshold on the electrocardiogram (i. e. -0.1mV of ST depression) in relation to work load (46+/-16 vs. 78+/-20 watts), HR (96+/-13 vs. 117+/-13 bpm), SBP (160+ /-20 vs. 199+/-31 mmHg) and DP (15400+/-3400 vs. 23400+/-4900 bpm × mmHg) . In elderly persons, DPBP could be determined without the ischemic ST depression in 96% of 327 tests. This study indicated that the DPBP would be an objective index of exercise intensity with lower risk for exercise prescription in cardiac patients and elderly persons.
ABSTRACT
Recently, supplements for athletes are being increasingly used. To clarify the current status of supplement intake, we conducted a survey in female university long-distance runners.<BR>An anonymous questionnaire survey was conducted in runners who participated in the 18th Japan Inter-University Women's EKIDEN Championship, We investigated 99 respondents.<BR>The survey showed that 86 runners (87%) took supplements. Iron was most frequently taken (68 runners, 69%) . The common purpose was to reduce fatigue (amino acids, vitamin C) and prevent ane mia (iron) . However, some supplements were taken after their effects were realized, while others were taken without an effect. In some cases, the purpose was not consistent with the effects. Most runners (73%) purchased supplements in shops stores. Fifty percent of them took supplements for supplementation of nutrients deficient in diets. More than 50% of the runners obtained information on nutrition from their coaches.<BR>Furthermore, most runners began to take supplements when they were senior (55 runners, 56%) or junior (31 runners, 31%) high school students. About 70% of them have taken iron. In the highest percentage of them, their coaches recommended the use of supplements.<BR>The results of this survey showed that most female university long-distance runners took supplements, and that a high proportion of them began to take them when they were senior or junior high school students, suggesting the widespread use of supplements among young athletes. In addition, their instructors markedly influenced the runner's nutritional outlook, by being the source of information on nutrition.
ABSTRACT
To clarify changes in body temperature during endurance exercise in patients with spinal cord injury (SCI), we measured tympanic temperature (Tty) and skin temperature in the head, arm, chest, thigh, shin and calf in 5 patients with SCI (T6-T 12) and 7 normal controls during 30 minutes arm cranking exercise (20 watts) from 10 minutes before the initiation of exercise until 10 minutes after the termination of exercise in an artificial climate room at a temperature of about 25°C with a relative humidity of about 50%. The Tty in the SCI group was lower than that in the control group from 10 minutes before the initiation of exercise to 10 minutes after the termination of exercise with a significant difference only at the initiation of exercise. The difference in Tty slightly decreased with continuation of exercise. The Tty in the SCI group at rest was 36.05-37.15°C. Four patients in this group showed a decrease of 0.04-0.12°C in the early stage and an increase of 0.66°C±0.19 (mean±SD) at the end of exercise over the value at the initiation of exercise.<BR>The skin temperature was lower in the SCI group than in the control group in all sites excluding the arm. Significant differences were observed in the head in the early stage of exercise and after exercise, in the chest from 10 minutes before the initiation of exercise to 5 minutes after the termination of exercise, in the thigh from 10 minutes before the initiation of exercise to 10 minutes after the termination of exercise, in the shin 10 minutes and 5 minutes before the initiation of exercise, and in the calf from before to 15 minutes after the initiation of exercise. In the SCI group, marked individual differences were observed in the skin temperatures in the thigh, shin, and calf, suggesting specificity of the skin temperature response in and near the paralysis area.<BR>Results in Tty in this study suggested no heat retention in the SCI patients. Therefore, the risk for heat disorders seems to be low during moderate or mild exercise under moderate temperature environment at a temperature of about 25°C with a relative humidity of about 50% even when the skin temperature is low, and thermolysis is not marked.