In the present study, we examined whether GLUT4 concentration in rat skeletal muscle is dependent on local muscle activity level or not. In ten male Sprague-Dawley rats, one side of gastrocnemius muscle was tenotomized, and the other side contralateral muscle was treated sham operation as a control. Gastrocnemius and plantaris muscles were excised from both legs at the five weeks after surgery. After the muscles were weighed, GLUT 4 concentration and citrate synthase (CS) activity were measured. The results are summarized as follows:
In gastrocnemius muscle, tenotomy induced decreases of 25% in muscle weight, 16% in CS activity, and 25% in GLUT 4 concentration as compared with the control muscle. These data suggest that although extramuscular environment is similar, different GLUT 4 concen-tration in both muscles is induced by different muscle activity level. Therefore, it is con-cluded that muscle activity level regulates GLUT 4 concentration in skeletal muscle. In over-loaded synergistic plantaris muscle, muscle weight and GLUT 4 content per whole muscle were increased by 18% and 17%, respectively, but GLUT 4 concentration and CS activity were not changed as compared with the control muscle. These data could be interpreted that GLUT 4 concentration and mitochondrial oxidative enzyme activity in skeletal muscle are coregulated.

Forty-eight male Wistar strain rats have been used to study the effect of voluntary exercise training on the succinate dehydrogenase (SDH) activity, blood lipids, and adrenal catecholamines. The animals were trained for 10 weeks with a voluntary running in revolving wheels. SDH activities in heart and skeletal muscles, total cholesterol and triglyceride in serum and adrenal catecholamines were determined right after rats reached a peak distance of voluntary running and at the end of training. Training produced no significant increase in the SDH activities of cardiac and skeletal muscles at 13 and 17 weeks of age. Physical training reduced 12%of serum cholesterol concentration (p<0.05) . The serum triglyceride concentration of trained group remained lower than that of the sedentary throughout a period of training (p<0.05) . The voluntary exercised rats had higher adrenal catecholamine concentration as compared with the sedentary at 13 weeks old (p<0.05), but there was no significant difference at 17 weeks old. These data demonstrated that voluntary training did not increase endurance capacity, and adrenal catecholamines, but lowered serum lipid levels.

Nutritional profiles in middle-aged trained and untrained women were compared both before and after menopause. Subjects were assigned to one of four groups : (1) pre-menopausal trained (Pre-T: n=14, aged 43±5 years, running distance 56±27 km/week, Vo₂max 49±4ml/ kg/min, mean±SD), (2) pre-menopausal untrained (Pre-UT: n=25, 42±5 years, 34±5 ml/kg/ min), (3) post-menopausal trained (Post-T: n=19, 53±3 years, 49±17 km/week, 42±6 ml/ kg/min), (4) post-menopausal untrained (Post-UT: n=26, 54±3 years, 31±3 ml/kg/min) . There were no significant differences in hematocrit (range 38.7 to 39.3%), hemoglobin (12.8 to 13.1 g/dl) and total protein (6.9 to 7.1 g/dl) among the four groups. Serum iron concentrations in the post-menopausal women (Post-T: 97±30μg/dl, Post-UT: 106±29μg/dl) were relatively higher than in the pre-menopausals (Pre-T: 85±35 pg/dl, Pre-UT: 78±33 pg/dl) . Mean total iron binding capacity in Post-UT (326 pg/dl) was lower than other groups (352 to 361 pg/dl) . Higher serum ferritin levels were observed in the post-menopausal women (Post-T : 35.8±27.5 ng/ml, Post-UT : 60.4±47.1 ng/ml) than the pre-menopausals (Pre-T: 18.3±13.1 ng/ml, Pre-UT: 16.6±10.7ng/ml) . Intake levels of the four groups with regard to the major nutrients were sufficient as compared with the recommended dietary allowance appropriate for age, sex and physical activity level. Intakes of calcium, iron and vitamins B₁, B₂ and niacin were higher in the trained groups than in the untrained. Regularly performed endurance exercise resulted in higher protein and iron intakes associated with higher energy intakes both before and after menopause. These results suggest that nutritional status of middle-aged women who regularly perform vigorous endurance running could be adequate for maintaining their health in a good state.

In this study, we investigated the possibility that GLUT4 protein concentration and mitochondrial enzyme activity is coregulated by muscle contractile activity. In the first experiment, male rats were trained by treadmill running or swimming for 3 wks and training effects in upper-and hind-limb muscle were investigated. Treadmill training program induced increases of 30% in citrate synthase activity, 51% in hexokinase activity, and 35% in GLUT4 protein concentration in hind-limb soleus muscles without causing training effects in upper-limb epitrochlearis muscles. On the other hand, swimming training program induced increases of 67% in citrate synthase activity, 139% in hexokinase activity, and 89% in GLUT4 protein concentration in epitrochlearis muscle without causing training effects in soleus muscles. These results suggest that muscle contractile activity which raises mitochondrial enzyme activity increases GLUT4 protein concentration in skeletal muscle. In a second set of experiment, we investigated relationship between muscle GLUT4 protein concentration and mitochondrial enzyme activity by use of the various type of rat muscles (soleus, plantaris, red gastrocnemius, white gastrocnemius, epitrochlearis and heart), which possese different contractile activity level. Significant correlation was observed between GLUT4 protein concentration and citrate synthase activity among different muscles (r=0.936) . They suggest that muscle GLUT4 protein concentration and mitochondrial enzyme activity level may be coregulated according to muscle contractile activity level.

The effect of chronic exercise on heart weights, succinate dehydrogenase (SDH) activities, and norepinephrine (NE) concentrations was examined in the Wistar-Kyoto (WKY) and Spontaneously Hypertensive (SHR) rats. Nine week old animals were trained either by forced treadmill running (26.8 m/min-1 hr/day) or voluntary exercise in running wheels (@9, 000 m/day at peak) for 12 wks. Male rats subjected to forced treadmill running program gained weight significantly more slowly than sedentary freely eating controls (p<0.01) . Heart ventricles of exercised groups in WKY rats were heavier than those of the sedentary controls (p<0.05) . Ratio of heart ventricle weight to body weight of male SHR and WKY rats was significantly higher in the runners than in the sedentary controls (p<0.01) . SDH activities of the red gastrocnemius muscle were 30 and 100% greater (p<0.01) for the voluntary and forced exercise animals, respectively, than the sedentary controls. Changes in muscle enzyme activity and heart weight were used to verify that the forced exercise program had produced a trained state. Blood pressure (BP) of voluntarily exercised SHR was 10% less at 15 wks (p<0.05) and remained lower until the end of training than that of control SHR, whereas BP of forced-trained SHR was not lowered. There was no measurable change in BP of WKY rats as a results of training. The voluntary exercise program had no effect on the concentrations of NE in heart and adrenal glands of SHR and WKY rats. The NE concentrations of heart and adrenal gland in forced/trained SHR and WKY rats were @10-40% greater than those of sedentary controls. The results of these experiments indicate that chronic exercise can depress the blood pressure of SHR rats. However, difference between two types of exercise training suggests that the endurance capacity improved by chronic exercise may not be a primary factor to delay the onset of the hypertention.

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.

The basal metabolic rate (BMR) of 70 postmenopausal women (age: 60.6±4.2 yrs., height: 154.9±5.2cm, body weight (BW) : 52.7±6.2kg; mean ±SD) was evaluated in relation to body composition (body fat mass (FM) : 17.3±3.9kg, lean body mass (LBM) : 35.3±3.6kg) . BMR was 1, 148±126kcal/day, 21.9±2.2kcal/kgBW/day, 32.7±3.2kcal kgLBM/day in all subjects. BMR (kcal/day) significantly correlated with BW (r=.635, p<0.001) and LBM (r=.598, p<0.001) . When divided into two groups, (lower %fat group (LF; <35%fat) and higher %fat group (HF; ≥35%fat) ), BW and FM were significantly higher in HF than in LF (BW: 56.6±6.4 vs 51.0±5.3 kg, FM: 21.7±2.8 vs 15.5±2.7 kg, p<0.001, respectively) . No difference was observed in LBM between the two groups (34.9±3.9 vs 35.5±3.5 kg) . BMR (kcal/kgBW/day) was lower in HF than in LF (21.0±1.8 vs 22.3±2.3, p<0.05), but HF group had higher BMR in terms of kcal/kgLBM/ day than LF (34.0±3.1 vs 32.1±3.1, p<0.05) . Multiple regression analysis was performed to predict BMR. A single predictor LBM and a pair of predictors LBM and FM explained 35.7% and 42.7% of the variance of BMR. This study suggested that a decrease in LBM is a major factor in affecting the reduction of BMR in postmenopausal women, whereas FM gained after menopause could be considered to have metabolic activity related to BMR.

The purpose of the study was to develop new VO_2max prediction models for Japanese men using a 3-minute walk test. One hundred and twenty-seven Japanese men aged from 20 to 69 years were recruited as subjects of the present study. Maximal oxygen uptake (VO_2max) was measured with a maximal incremental test on a bicycle ergometer. The prediction models were derived using data of age, 3-minute walking distance (3MWD), and either BMI, waist circumference (WC), or %Fat. This data was cross-validated by using PRESS cross-validation procedures. 3MWD was significantly related to VO_2max (r = 0.54, P<0.001). The multiple correlation coefficients for the BMI, WC, and %Fat models, respectively, were 0.81, 0.82, and 0.85. The standard error of estimate (SEE) was 4.5, 4.4, and 4.1 ml·kg^-1·min^-1, respectively, for the BMI, WC, and %Fat models. All regression models demonstrated a high level of cross-validity supported by the minor shrinkage of the coefficient of determination and increment of SEE in the PRESS procedure. This study demonstrated that 3MWD was useful for predicting VO_2max accurately using VO_2max prediction models for Japanese men. The new non-exercise prediction equations derived in this study are applicable to estimating VO_2max in Japanese adult men.

The aim of the present study was to examine the validation of prediction equation of basal metabolic rate (BMR) in Japanese female athletes. The study population consisted of 122 Japanese female athletes (age 20.2 ± 1.3 years, height 162.5 ± 6.3 cm, body weight (BW) 57.4 ± 7.7 kg, and fat-free mass (FFM) 45.5 ± 5.1 kg). Body composition was estimated by using air displacement plethysmography (BOD POD System). BMR was measured by indirect calorimetry using dougras bag tequnique, and predicted BMR was calculated from different equations based on FFM. When compared with measured BMR, predicted BMR from the equation of Taguchi et al. (BMR (kcal/day)= 26.9×FFM (kg)+ 36) and equation of Owen et al. were not significantly different. Whereas, predicted values from equation of Japan Institute of Sports Sciences, National Institute of Health and Nutrition and Cunningham were significantly different from measured value. Estimation error and Total error were smaller in equation of Taguchi et al. and Owen et al., however, equation of Owen et al. had a larger estimation error in the subjects who was small body size (less than 42kg) or large body size(more than 69kg). Furthermore, newer equation of Taguchi et al. (BMR=27.5×FFM+5) was developed from the pool data (n=205) in the present study. Standard error of estimation (SEE) of this equation was smaller than the equation of Taguchi et al., and systematic error was hardly observed.In conclusion, the newer equation of Taguchi et al. developed from measured BMR of Japanese female athletes was useful to predict BMR.