Near infrared spectroscopy has been used to determine the chemical composition of food stuffs, i, e., the protein, fat, and moisture content. Recently in the U. S. A, this technique was applied to the estimation of human body composition, and a portable instrument was developed. This study was designed to determine the prediction equation of body fat for Japanese people. 69 men and 52 women, aged 18 to 58 years, covering a wide range of percent fat levels, physiques, physical activity levels, had body fat estimated by hydrostatic weighing (HW), skinfold thicknesses (SF) and near infrared spectroscopy. Near infrared interactance spectra were measured on the anterior midline of the biceps halfway (between the anticubital fossa and acromion), the spectral data from which gave best correlation with HW and SF compared the other sites, using the wavelength of 947 nm. The spectral values and percent fat values obtained from HW about 1/2 of subjects were used to develop a prediction equation. This equation was then used to predict % body fat of the other 1/2 subjects. The correlation coefficient between % body fat as predicted by the near infrared method and as predicted by the HW technique was 0.88 (p<0.001, SEE=3.2) . This correlation value was similar to the value between % body fat as predicted by HW and as predicted by SF. In the American data, the correlation coefficients were higher when the other variables were added ; height, weight, age, but in the Japanese they did not almost change even when the other variables were added. There was not a difference between the spectra of right and left arm values. In the results, the prediction equation of % body fat for the Japanese population was determined as follows: % body fat =54.14-29.47× (the spectral data at 947 nm) [r=0.88, p<0.001, SEE=3.2] (for right arm) .
Recently, bioelectrical impedance analysis systems (BIA) have become available for determination of human body composition. The validity of BIA has been found to be sufficiently in the American population. However, more work is needed to assess the validity and applicability of BIA to the Japanese population. The purposes of this study were (1) to test the validity of body composition measured by BIA in comparison with the underwater weighing criterion method, and (2) to develop a convenient equation that would reliably predict body composition using BIA and anthropometric measurements in Japanese females. The subjects were 226 Japanese women and girls aged 11 to 55 years (23.9±8.3) . Body impedance was measured using a tetrapolar electrode method, with a localized 800-μA and 50-kHz current injection (Selco SIF-881) . The percentage of body fat (%fat) estimated by BIA was significantly correlated with densitometrically determined %fat (r=0.793, Lukaski et al, method ; and r=0.800, Segal et al, method) . The magnitude of these correlations was substantially higher when compared with r=0.615 found between the skinfold thickness method and the criterion method. Absolute %fat values estimated by BIA were, however, significantly lower than those determined by the criterion method, thereby indicating the need for a more accurate method of assessing Japanese body composition. For this, we propose the use of D=1.1303-0.0726 (Wt×R/Ht2), where D=body density in g/ml, Wt=body weight in kg, R= (R2+Xc2) 0.5 in ohms, and Ht=body height in cm. Lean body mass (LBM) and %fat predicted from this equation were correlated significantly (r=0.924 and r=0.799, respectively) with values determined by densitometry. The standard error of estimates of LBM and %fat resulted in figures of 1.9 kg and 3.7%, respectively. Thus we suggest that BIA is valid, convenient, and inexpensive, and that the prediction equation proposed in this study is useful for assessment of body composition in Japanese adult females.
The purpose of the present study was to clarify if hyperoxic training would be more effective on endurance capacity and performance at sea level than normoxic training. Twelve healthy males who had not been performing any regular endurance training participated in this study as subjects. They were divided into the two groups on the basis of their Vo2max ; one was the hyperoxic training group (Hyperoxic G) and the other was the normoxic training group (Normoxic G) . Training intensity of Hyperoxic G was 85% of Vo2max obtained breathing hyperoxia (a gas mixture of 60% O2 in N2) . That of the Normoxic G was 85% of Vo2max obtained breathing room air. Duration of the daily training was 10 min in the former, and 10 min 22 sec to 11 min 30 sec in the latter ; thus, the amount of work was equal for both groups. Training frequency and period was 3 days/week and 4 weeks, respectively. After training, all-out time and lactate threshold in the Normoxic G was significantly enhanced from 17 min 18 sec to 19 min 7 sec and 19.6 ml/kg⋅min to 23.0 ml/kg⋅min. But, Vo2max, maximal ventilation and heart rate during training were not significantly changed. On the other hand, in the Hyperoxic G, not only all-out time and lactate threshold were significantly enhanced from 17 min 56 sec to 19 min 33 sec and 19.7 ml/kg⋅min to 24.9 ml/kg⋅min, but Vo2max and maximal ventilation were significantly increased from 46.1 ml/kg⋅min to 51.0 ml/kg⋅min and 117.3l/min to 135.1 l/min. Furthermore, heart rate during training was significantly decreased. From these results, it was concluded that hyperoxic training would be more effective in improving endurance capacity than normoxic training.
The effects of exercise training on bone development in growing rats were studied using the photon-absorption method and histomorophological analyses. Thirty-seven male Wistar strain rats at 4 wks of age were divided into five groups : sedentary control (C; N=7), 15 min/day training (T 15 ; N=6), 30 min/day training (T 30 ; N=8), 60 min/day training (T 60 ; N=8) and 120 min/day training (T 120 ; N=8) . All rats in these training groups were subjected to a treadmill running at a speed of 30 m/min, 5 days/wk for 11 wks. The results of our study were summarized as follows : 1) Fat-free dry weight of the tibia was significantly heavier in T 30, T 60 and T 120 than C and T 15, respectively. 2) Bone mineral content (mg/cm) of tibial midshaft in all T groups was significantly higher than that in C group, respectively, while no differences were found between any of the training groups. 3) On histological parameters of cross-sectional samples from tibia, such as cortical area, total area and appositional growth rate on periosteum, higher values were observed in T groups compared with C group. These results suggest that physical training induce markedly facilitative girth growth associated with elevated bone formation of periosteum in the tibia, and moreover, the daily exercise duration does not change the degree of bone hypertrophy.
The effect of swimming training on creatine ki nase (CK) isoenzyme compositions (cytoplasmic CK : CK-MM, -MB, -BB ; mitochondrial CK : m-CK) of coleus (SOL), extensor digitorum longus (EDL) and heart muscles were studied. Wistar strain male rats were trained by swimming at a water temperature of 38±2°C, loaded with a weight equal to 5% of their body weight attached to their tails, and made to swim 4-days per week from the age of 4 weeks old for 4, 6 and 8 weeks. CK isoenzyme compositions of SOL, EDL and heart were different from those of other muscles. The activities of CK-MB and m-CK of SOL, EDL and heart increased following exercise training. CK isoenzyme composition of skeletal muscle (SOL and EDL) tended to qualitatively resemble the heart with training. These results suggest that the training-induced metabolic change in skeletal muscle causes similar CK isoenzyme composition to the heart muscle, and ensure energy production for the continuous muscle contraction during endurance exercise. The possibility that the source of the increased serum CK-MB activity after exercise is from the skeletal muscle should be examined thoroughly when the high serum CK-MB activity is interpreted.
A study was performed to evaluate the physiological function of elite senior high school soccer players (Kunimi) . Forty-six players were evaluated for cardiorespiratory function (maximum oxygen uptake : Vo2max, maximum oxygen debt : Max O2 debt), body composition (underwater weighing) and skinfold thickness, all parameters being measured four times over a two-year period. The following means were recorded : age, 17.8 yr ; height, 173.0 cm ; weight, 65.8 kg ; percentage body fat (%Fat), 10.0%; lean body mass (LBM kg), 59.2 kg ; LBM/Ht (kg/m), 34.2 ; sum of eight skinfold thicknesses, 63.5 mm ; Vo2max, 60.0 ml/kg⋅min ; maximum ventilation (VEmax, BTPS), 136.8l/min ; maximum oxygen debt ; 8.2l, 124.8 ml/kg. Results for percentage body fat, Vo2max (ml/kg⋅min) and Max O2 debt (ml/kg) were compared with values found in other soccer players at various levels. In summary, one of the most outstanding attributes of the Kunimi senior high school soccer players was a high level of both aerobic power and anaerobic power.