Thirty-nine 50-days-old female rats of Wistar strain were divided into three dietary groups (high carbohydrate, high protein, high fat), and each dietary group was further divided into sedentary and exercising subgroups. While the sedentary rats were housed in individual small cages all day long, the exercising rats were subjected to one-hour treadmill running 6 days/week.
After the 5-week experimental period, the following results were obtained.
1) No difference in the increase of body weight was observed between sedentary and exercising rats of the high carbohydrate dietary group. In the high fat dietary group sedentary rats, and in the high protein dietary group exercising rats, gained significantly greater body weight. Increase of body weight varied among sedentary subgroups of different diets, but not among exercising subgroups.
2) Body fat content was significantly higher in sedentary than in exercising rats of all three dietary groups. Lean body mass and protein content of gastrocnemius and heart were greater in exercising than in sedentary rats. Liver fat content was significantly lower in exercising than in sedentary rats of high carbohydrate and high fat dietary groups. Lean body mass and muscle prontein content were highest in high protein dietary exercising group.
3) Effecs of diet and exercise on blood composition were not clarified, but at least exercising rats did not show any sign of anemia. No significant difference in weight and length of tibia and femur was obserbale among groups.

The relationship between exercise habit and physical fitness in aged individuals was studied in 179 urban residents aged 60-89 years (82 males and 97 females) by a battery of physical performance tests. Eighty-seven point eight percent of the males and 88, 5% of the females were regularly engaged in some kind of exercise, most frequently walking (45.8% of the males and 37.7% of the females), followed by tending plants, croquet, and light exercise (about 30% each) . More strenuous exercise such as swimming, tennis, and jogging was done by 2-3%. The results of the tests were better in individuals who exercised regularly than those who did not, and the differences were significant in grip strength, breath holding, and total score in the males and in all items except grip strength in the females. Physical performance also differed among those who exercised according to the frequency, duration, and intensity of the exercise, but the differences were smaller than between those who exercised and those who did not. From these findings, relatively mild exercise is considered to be effective for preventing (or delaying) the decline of physical fitness in aged individuals.

To develop a simple test of endurance capacity in the elderly, we evaluated the reliability and validity of the shuttle stamina walk test (SSTw), in which the running in the shuttle stamina test (SST : 3-minute shuttle running along a 10-meter course) was changed to walking.
We found that: 1) The walking distance in the SSTw was correlated with Vo₂max (r=0.827), 2) the walking distance showed a correlation between the first test and a re-test (r=0.853), 3) the mean peak heart rate during the test was 86.3% of the estimated maximum heart rate with no difference according to age or sex, 4) subjective evaluation of the intensity of exercise was expressed as“fairly light”or“somewhat hard”by 73.7% of the subjects, 5) the results of the SSTw reflected the subjects' self-evaluation of endurance capacity, and 6) the age-related percentage reduction of the walking distance in the SSTw was similar to that in V₂max in subjects aged 40 years and above.
These results suggest that the SSTw, a simple test of endurance capacity that can be performed safely over a wide range of middle-aged to elderly people including those in late old age and those with a low fitness level, has sufficient reliability and validity.

In the context of energetics related to a pendular model, the mechanical power (W) and ‘pendular motion efficiency’ (PME) were determined during walking of the subjects who consist of 37 healthy elderly women (65-85 years) and 21 young women (18-25 years) . Using a force plate, the potential and kinetic energies of the body's centre of mass were measured at various constant speeds. Walking speeds were selected and controlled by a newly devised pace-maker. PME, which is equivalent to ‘% recovery’ by Cavagna (1976), indicates a sort of efficiency in transforming potential energy into kinetic energy and vice versa. The external power to accelerate the body (Wext ), which is thought to be supplied by muscles, increased with walking speed, and the rate of increase in Wext tended to be greater in the elderly than in the young subjects. It was noted that the maximal PME values at the optimum speed in both age groups were comparable, but PME values in the elderly decreased more markedly than in the young subjects as walking speed deviated from the optimum. This fact suggests that an adaptability to different walking speeds reduced in the elderly population.

Although skeletal muscle mass decreases with aging, its decrease rate may differ among parts of the body. There have been few studies examining the differences in the muscle mass decrease rate between proximal and distal parts of the limbs or between the left and right legs in a large population. Bioelectrical impedance (BI) index, calculated as the ratio of the square of segment length to impedance, is linearly correlated with the muscle mass calculated by MRI (r=0.902-0.976, p<0.05, Miyatani et al., 2001) in the limb segments. The purpose of this study was to examine differences in the decrease rate of muscle mass between the proximal and distal parts of the limbs and between the upper and lower limbs in healthy Japanese. The BI index was measured in the bilateral thighs, lower legs, upper arms, and forearms of 1006 healthy Japanese men and women (aged 15-97 years). While the BI index decreased with aging in all examined parts of the body, the decrease rate was larger in the lower limb than in the upper limb, and in the thigh than in the lower leg. The percentage of people who showed a difference of more than 10 % in the BI index between the left and right lower limbs was significantly higher in the elderly than in young subjects. These differences in the decrease rate of muscle mass between limbs may be associated with decreases in physical functions in the elderly.

In this study, the states of obesity, physical activity, and diet of 4 th-6 th graders were examined in an agricultural area of the Tohoku region, where many pupils are driven to and from school. The physique (height, weight), physical activity level (Select 2 ; Kenz), and nutritional intake were investigated in 32 elementary school pupils for one week.The subjects showed the following characteristics : 1) A high percentage of obese pupils, 2) a small number of walking steps, and 3) a lower percentage of obese pupils than non-obese pupils participating in sports activities. Therefore, efforts to increase the physical activity level are considered to be necessary for the prevention of obesity. For this purpose, in addition to administrative measures to increase exercise opportunities in the community such as the establishment of a general sports club, local movements such as encouraging pupils to walk to school may be effective.

An Elderly Health and Fitness Promotion Program was carried out in the 32 on areas of Ichihazama Town (now Kurihara City), Miyagi Prefecture to promote the health of the elderly population by making as many townspeople as possible aware of their health and fitness levels, and develop active lifestyles. We evaluated the effectiveness of this program on the basis of the results during the past 4 years.In 2001, the Elderly Health and Fitness Promotion Program was started in each of the town's 32 administration areas. The number of participants continued to increase until it exceeded 600 in 2004, with increases in the percentages of males, those aged 80 years or above, and those withlimited ADL among the participants. While the results of fitness tests varied widely and were very low in some participants, changes in the fitness level were small in regular participants.

Physical fitness of 900 volunteers over 60 years of age were analyzed using a 6-item battery test to obtain fundamental data on the fitness status of the aged Japanese. The test battery consisted of stepping, vertical jump, grip strength, breath holding, body flexion and one-leg balancing, and could be performed safely with relatively mild physical stress in the elderly after simple screening by measurement of resting blood pressure and oral check on mobility problems of the knee and the hip. Males showed significantly higher values in vertical jump, grip strength and breath holding, while females showed significantly higher values in body flexion. There were no sex differences in stepping and one-leg balancing. Lowing trend was found in the score with age in all items except breath holding, but the extent of the reduction differed among the measure elements of fitness. Most of measured items showed significant correlations each other. The values obtained with this test are considered to be useful for future analysis of the fitness of aged people and also to determine the exercise appropriate for them.

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.