The purpose of this study was to assess the validity of activity record (AR), accelerometer (AC) and heart rate (HR) methods in comparison with the doubly-labeled water (DLW) method as the criterion measure of total energy expenditure (TEE) in high school students undergoing vigorous activities. Twelve baseball players in Japanese high school (16.5±0.5 yrs) were monitored for seven consecutive days. TEE values obtained over a 3-day-period by AR, AC and HR were simultaneously validated against TEE measured by DLW over a 7-day-period. TEE value measured by DLW was 4922±391 kcal/day. The Physical activity level (PAL=TEE/BMR (basal metabolic rate)) was 2.66±0.14. TEE estimated by AR, AC and HR was significantly different from DLW, with mean differences of -13.9±6.5%, 35.3±3.6% and 31.6±23.9%, respectively. However, TEE estimated by AC and AR significantly correlated with that measured by DLW (r=0.73, r=0.70, p<0.05, respectively). The limits of agreement between DLW and AR, AC and HR were from -1350 kcal/d to -21 kcal/d, -2293 kcal/d to -1192 kcal/d, and 3875 kcal/d to -797 kcal/d respectively. AC was superior to the other methods. However, the limits of agreement in AR were similar to AC. These data suggest that on accuracy and precision, AR would be superior to the other two for predicting TEE in high school students undergoing vigorous activities. However, AC has the advantages being able to examine patterns of activity over long periods of time without interfering with normal movement and the ability to store data continuously over long periods of time. Therefore, it was suggested that, simultaneously, the AR and AC methods are accurate predictors of TEE and patterns of activity while undergoing sports vigorous activities.

The purpose of this study was to examine the effects of walking 10,000 steps/day on the body composition, blood pressure, blood biochemical parameters and physical fitness. Sixty-one women, aged 56.0±5.3 yrs (mean±SD), participated in a hyperlipemia prevention program. The length of the program was 90-min and it was performed one time per week for 3 months. The program consisted of stretching and aerobic exercise (cycle exercise, walking or aerobic rhythmic gymnastics). The participants were asked to walk 10,000 steps/day or more during the program. The number of steps and physical activity (PA) were monitored using a single-axis accelerometer during the program. PA was categorized into three activity levels, namely light (L), moderate (M) and vigorous (V) PA. After 3 months in the program, the participants were divided into two groups according to the average number of steps taken daily during the program : one group (GA) walked more than 10,000 steps/day, while the other (GB) walked below 10,000 steps/day. The time spent in LPA, MPA and VPA in GA were significantly longer than in GB (LPA : 79.4±19.2 min VS 58.2±10.0 min, MPA : 38.5±9.6 min VS 21.6±6.1 min, VPA : 6.3±4.9 min VS 2.6±2.0 min, p<0.001). Decreases in the percent body fat (p<0.001), body fat mass (p<0.001), fasting glucose (p<0.001), hemoglobin A1c (p=0.026), and triglyceride (p=0.036) and an improved performance when balancing on one leg while standing with eyes closed (p=0.027) were found respectively after the program for GA. These findings indicated that GA affected the percent body fat (p=0.036), body fat mass (p=0.040) and fasting glucose (p=0.009). According to a stepwise multiple regression analysis, the time spent in MPA showed a significantly negative correlation with the change in the body fat mass (p=0.025), and the change in the body fat mass showed a significantly positive correlation with the change in the fasting glucose (p<0.001), hemoglobin A1c (p=0.002) and triglyceride (p<0.001). We thus concluded that walking 10,000 steps/day resulted in an increased amount of time spent in MPA, and thus leading to decrease in the amount of body fat. This decrease in body fat is also considered to contribute to improvement in the coronary risk factor profiles.

The purpose of this study was to investigate the effect of changes in post-absorptive resting metabolism (PARM) on plasma triiodothyronine (T3) levels under a prescribed diet. The subjects were 31 sedentary female college students (19.9±0.9 yrs). Subjects stayed in a metabolic ward at the National Institute of Health and Nutrition for 18 days. PARM was measured 4 times during the experimental period. Additionally, blood was collected 4 times during the experimental period, and general health care including the measurement of thyroxin by blood biochemical examination was carried out. Subjects were divided into three groups (n=26, n=4, n=1), two of which were analyzed for this study. The two groups were divided according to thyroid function: Group N (n=26) included subjects in which T3 was judged to be within the normal range during the experimental period; Group L (n=4) included subjects for whom T3 was not normal during the study period, and was judged to be under the normal range at least once. The remaining 1 subject had a T3 judged to be over the normal range.For Group N, several parameters decreased significantly during the course of the experiment: weight was 51.5±4.97 vs. 50.8±4.3 kg (p<0.01); T3 was 1.16±0.19 vs. 1.01±0.12 ng/ml (p<0.01); and PARM was 3.1±0.2 vs. 2.9±0.2 ml/min/kg (p<0.05). For Group L, several parameters also decreased significantly during the course of the experiment: weight was 53.6±4.9 vs. 52.6±4.5 kg (p<0.01); T3 was 0.94±0.15 vs. 0.75±0.07 ng/ml (p<0.01); and PARM was 2.9±0.2 vs. 2.7±0.1 ml/min/kg (p<0.05). The average PARM of Group N was significantly higher than that of Group L (7.0%). PARM during the luteal phase of the menstrual cycle was significantly higher than during the menstrual phase (3.5 %), in subjects for whom the phases of the menstrual cycle were distinguishable (n=13).According to the 2005 Dietary Reference Intakes (DRIs) for Japanese, the basal metabolic rate (BMR) is calculated at 23.6 kcal/kg body weight/day, or 3.27 ml/min/kg translated for VO₂ for women within the 18~29 year age group. However, the values calculated from the measurements of this research study were approximately 9.5% lower for Group N and 15.8% lower for Group L than that of the DRIs.Future investigation is required to explain the reasons for the difference in PARM between this study and that of previous ones.

In this study, we investigated the effects of a 2-year swimming program on suppressing bone loss in postmenopausal women. There were 22 subjects who participated in the swimming program (mean age 59.5 yr) and 19 controls (mean age 59.3 yr) . The program consisted of one-hour exercise sessions ; and the swimmers had on average 1.5 sessions per week. BMD at the lumbar spine (L2-L4) and proximal femur (neck, trochanter, and Ward's triangle) were measured by dual X-ray absorptiometry (DXA) ; and leg extensor power was measured using a dynamic leg extensor power rig. All the measurements were taken at baseline, 1 and 2 years. Height, weight, calcium intake and daily activity profiles were similar between the two groups, and these changed little throughout the experiment. In regard to leg extensor power, the swimming group had a significant increase at 1 and 2 years. At 2 year, the swimming group demonstrated 4.4%, 5.7% and 3.4% increases in BMD at the femoral neck, trochanter and Ward's triangle, respectively, while the control group showed slight decreases of BMD at the femoral neck (-0.2%) and Ward's triangle (-1.4%) . Significant differences in the rate of change in BMD at each site were observed between the two groups. The swimming group showed a decrease in lumbar spine BMD, as did the control group and the rate of the decline did not differ between the two groups. This study suggests that a 2-year swimming program for postmenopausal women can induce the beneficial effects of retarding bone loss at the proximal femur site and increasing leg extensor power.

This study was designed to evaluate effects of long-term swimming training on maximal aerobic capacity and sernm lipid and lipoprotein profile of postmenopausal women. In the first study, 12 swimming-trained postmenopausal women (age: 58±3 yrs, BMI : 22± 2 kg/m², training distance : 3.6±1.6 km/wk, mean±SD) were compared cross-sectionally with 50 age-matched untrained women (58±5 yrs, 23±2 kg m²) . Swimming-trained women had higher maximal oxygen uptake (Vo2max) than untrained (34± 5 vs. 30± 5 ml/kg/min, P<0.05) . Serum total- and HDL-cholesterol (T-C and HDL-C) and triglyceride (TG) concentrations in swimmers were similar to those in untrained (T-C: 232±23 vs. 220±44 mg/dl, HDL-C : 69±15 vs. 72±17 mg/dl, TG : 83±21 vs. 99±67 mg/dl) . On the other hand, swimmers had higher serum LDL-cholesterol concentrations (LDL-C) than untrained women (161±28 vs. 138±25 mg/dl, P<0.05) . The second study was conducted to test the effects of a 2-year swimming program on Vo2max and serum lipid and lipoprotein concentrations of postmenopausal untrained women. After the swimming program 10 trained women (age : 59±7 yrs, BMI : 23±3 kg/m², Vo2max : 30± 3 mlikg/min at baseline, training condition : one hour session, frequency: 1.5±0.4 times/week during the program) and 12 untrained women (60± 5 yrs, 23± 3 kg/m², 29± 5 ml/kg/min at baseline) were retested. No change in BMI was observed in the two groups. At the 2-year follow-up, the trained women increased Vo2max (34± 5 ml/kg/min, P<0.05), whereas no change in Vo2max was observed in the untrained women (30± 5 ml/kg/min) . No changes occurred in concentrations of T-C (Trained : 238±25 233±21 mg/dl, Untrained : 236±20 236±32mg/dl), HDL-C (Trained : 70 ± 15→74 ± 16 mg/dl, Untrained: 69 ± 15→69 ± 14 mg/dl), LDL-C (Trained : 150 ±29 144±27mg/dl, Untrained : 144±15→145±23mg/dl), and TG (Trained : 90±32 74±25 mg/dl, Untrained : 115±81 106±52mg/dl) . These results suggest that although a long-term swimming program can increase maximal aerobic capacity, favorable changes in sernm lipids or lipoproteins can not be expected for postmenopausal women.

Daily energy expenditure has been measured by the physical activity recording and/or the questionnaire method. Recently, the accelerometer or pedometer is used to measure daily energy expenditure. The purpose of this study was to examine validity of the pedometer with accelerometer and to compare the daily physical activity between young and older Japanese. To examine validity of the pedometer, 10 young subjects worn the pedometer (Lifecorder) on the waist and then performed the walking test. Energy expenditure was measured by the expired gas analysis during the test. Fourtythree young and 54 older subjects worn the Lifecorder on the waist during free-living condition for 14 days. The intensity of Lifecorder had a high correlation with the physical activity intensity (METs) (r=0.958, P<0.001) . In the free-living condition, daily energy expenditure was 2171±305 kcal in young and 1617±196kcal in older (P<0.001) . Total step in young was significantly higher than older (young: 9490±2359 steps ; older: 6071±2804 steps, P<0.001) . There was no significant difference in the duration of physical activities at the Lifecorder intensity 1 such as desk working, watching TV sitting on a sofa and driving a car. However, the duration more than the intensity 2 corresponding to 2.2 METs in young subjects was longer than that in older (P<0.001) . We concluded that in older subjects, not only amounts of daily energy expenditure but also intensities of daily living were lower compared to the young subjects.

The purpose of this study was to investigate the reappearance of the post-absorptive resting metabolic rate (PARM) during a prescribed diet. The subjects were 10 sedentary female college students (20.1±0.7yrs) . Thyroid function was judged in all of them to be within a normal range. Subjects stayed in a metabolic ward at the National Institute of Health and Nutrition for 18 days. The post-absorptive resting metabolic rate was measured 4 times during the experimental period. Moreover, blood was collected five times, and general health care including the measurement of thyroxin by blood biochemical examination was carried out. As for the actual metabolic measurements, a high reappearance was confirmed by the intra-individual coefficient of variation (CV) of the post-absorptive resting metabolic rate (3.5±1.8%) and the inter-individual CV (7.2%) . The smallest CV was the standard value of PARM/body surface area, followed by PARM/body weight, PARM/LBM, and PARM/urine creatinine. On the other hand, weight (50.8±4.9 vs 50.3±4.6 kg ; p<0.01), hemoglobin concentration (13.7 ± 0.5 vs 12.8±0.5g/dl ; p<0.05), serum total cholesterol level (194±41 vs 175 ± 37 mg/dl ; p<0.05) and post-absorptive resting oxygen uptake (0.149±0.01 vs 0.142±0.011/min ; p<0.01) decreased significantly during the experiment. According to the Japanese Recommended Dietary Allowances (RDAs) (1999), basal metabolic rate (BMR) was calculated at 1, 210 kcal/day or 23.6 kcal/kg body weight/day for women within the 18-29 year age group. But the results (the mean of all measurements) of this research suggested that this value was 1, 033 ± 79 kcal/day, or 20.7 ± 2.0 kcal/kg body weight/day based on the method of Weir ; and was approximately 10% lower than RDAs. Future investigation is required to explain the reasons for the difference in BMR between this study and that of previous ones.

The purpose of this study was to examine the effects of long-term habitual exercise on daily total energy expenditure (TEE) and its components, body composition and maximal oxygen uptake (VO₂max) in middle-aged Japanese women. Twenty-eight subjects aged 39 to 58 years were assigned either to a nonhabitual exercise group (Control ; n=12) or a habitual exercise group (Exercise ; n=16). TEE, physical activity level (PAL) and the daily physical activity energy expenditure (PAEE) were assessed by doubly labeled water (DLW) method. The exercise-induced energy expenditure (ExEE) and nonexercise-induced energy expenditure (NExEE) were evaluated based on the activity record investigation conducted simultaneously during the DLW measurement period. The result follows that TEE was significantly (p<0.01) higher in the Exercise group (2520 kcal · day^-1) than in the Control group (1921 kcal · day^-1). There was no significant difference in basal metabolic rate between the groups. PAEE and ExEE were significantly higher in the Exercise group than in the Control group (p<0.01). Habitual exercise induced an increase in TEE without resulting in a compensatory reduction of NExEE. The percentage body fat (fat%) was significantly lower in the Exercise group (25.5%) than in the Control group (30.9%). VO₂max was higher in the Exercise group (1788 ml · min^-1) than in the Control group (1417 ml. min^-1). After correction for body weight, fat% was negatively associated with TEE (p<0.01), PAEE (p<0.01) and ExEE (p=0.05), while VO₂max was positively associated with TEE (p<0.05), PAL (p<0.05), PAEE (p<0.05) and ExEE (p<0.01). These results suggest that habitual exercise is associated with the increase of TEE, the improvement of body composition and VO₂max. The improvement of VO₂max was mainly caused by the increase in ExEE, indicating that the exercise intensity is important to the improvement of cardiorespiratory endurance fitness.

The purposes of this study were to investigate the relationships between physical activity variables and physical fitness, and between amount and intensity of physical activity in children and adolescents. Subjects were divided into two groups : 178 children (99 boys aged 9.8±0.6 and 79 girls aged 9.7±0.6) who had not reached the age of peak height velocity (PHV), and 336 adolescents (141 boys aged 15.0±1.1 and 195 girls aged 15.3±1.2) who had reached the age of PHV. Physical activity level (PAL : total energy expenditure/basal metabolic rate) which indicates the amount of physical activity, and time engaged in each of physical activity intensity (light, moderate and vigorous), which indicates the intensity of physical activity were estimated from uni-axial accelerometer. Physical activity was monitored for 3 consecutives days : 2 weekday and 1 weekend day. Moreover, physical fitness test suggested by the Ministry of Education, Culture, Sports, Science and Technology was applied. Results of this study showed that PAL was closely related to physical fitness in children, while time engaged in vigorous activity was more related to physical fitness in adolescents. On the other hand, time engaged in light and moderate activity was closely associated with PAL in younger girls, whereas in younger boys, PAL was closely related to time engaged in moderate and vigorous activity. However, time engaged in moderate activity was more related to PAL in the adolescent group. These results suggest that the relationship between physical activity variables and physical fitness and between amount and intensity of physical activity might vary according to the growth development of boys and girls respectively.