The purpose of this study was to compare estimates of human body composition determined from single-frequency bioelectrical impedance methods (S-BIM) and multi-frequency bioelectrical impedance methods (M-BIM) . The human body composition was assessed by dual energy X-ray absorptiometry (DEXA), 5 brands of S-BIM, and 2 brands of M-BIM. Forty-five women, aged 26-58 years, served as subjects. The S-BIM and M-BIM fat-free mass (FFM) estimates were highly correlated with the FFM measured by DEXA (r=0.82-0.93) . The standard errors of estimate (SEE) for FFM were approximately 2 kg. With the exception of the MLT-100 (which slightly underestimated FFM), all brands of BIM slightly overestimated FFM. The absolute mean differences between FFMDEXA and each of the 7 BIM estimates ranged from -3.02 kg to 3.46 kg. Although the 7 brands of BIM provided slightly different estimates, the results of this study suggest that 5-BIM and M-BIM are relatively valid in human body composition.

The purpose of this study was to determine the loss of visceral fat during weight loss program with diet only or diet plus exercise in premenopausal obese women (age 44±6 yr) . One hundred seventeen women (body mass index 29±3 kg /m²) were divided into diet only group (DO, n=40) and diet plus exercise group (DE, n=77) . DE was further divided into two groups: a group with a small change in VO₂max (DE₁, n=26) and a group with a large change in VO₂max (DE₂, n=51) . Height, weight, fat mass, %fat, fat-free mass (FFM), abdominal total fat area (TFA), visceral fat area (VFA), subcutaneous fat area (SFA) and VO₂max (ml/kg FFM/min) were measured before and after weight loss. The changes of weight, fat mass, %fat were significantly larger in DE than in DO. No difference was found in the changes of weight, fat mass, %fat between the DE₁ and DE₂. Percentage of change in VFA was significantly larger in DE₂ (41±15%) than in DE₁ (31±16%) . These data suggest that both weight-loss programs (DO and DE) contribute to a remarkable decrease in visceral fat. Addition of exercise training, which would induce an improvement in VO₂max, to dietary restriction, may elicit a greater effect on visceral fat.

This study sought to examine the potential relationships of physical education (PE) participation at preschool and sports club (SC) participation out of school and daily physical activity (PA) measured objectively using a triaxial accelerometer, with physical fitness in preschool children. Physical fitness testing was used to measure both health-related and skill-related parameters of fitness in 191 Japanese preschoolers in the Kanto region (94 boys and 97 girls, 5.6 ± 0.6 years). Daily PA was assessed using a triaxial accelerometer (ActivTracer, GMS) for 6 consecutive days, including weekdays and weekend days. PE and SC participation was assessed using questionnaires for preschool teachers or parents of subjects, respectively. All health-related and skill-related physical fitness and total Z-score were correlated with time spent with physical activity ratio (PAR)≧4 when adjusted for age, sex, body height and weight. In addition, greater grip strength was associated with PE participation at preschool, and 25 m run speed was associated with SC participation, also. However, 25 m run speed was negatively associated with PE participation. These findings suggest that daily PA may contribute to the development of both health-related and skill-related fitness in preschool children, although further research on the cause-effect relationship is needed. Moreover, participation in a SC may contribute to the development of running speed.

The purpose of this study was to compare estimates of human body composition determined from single-frequency bioelectrical impedance methods (S-BIM) and multi-frequency bioelectrical impedance methods (M-BIM) . The human body composition was assessed by dual energy X-ray absorptiometry (DEXA), 5 brands of S-BIM, and 2 brands of M-BIM. Forty-five women, aged 26-58 years, served as subjects. The S-BIM and M-BIM fat-free mass (FFM) estimates were highly correlated with the FFM measured by DEXA (r=0.82-0.93) . The standard errors of estimate (SEE) for FFM were approximately 2 kg. With the exception of the MLT-100 (which slightly underestimated FFM), all brands of BIM slightly overestimated FFM. The absolute mean differences between FFMDEXA and each of the 7 BIM estimates ranged from -3.02 kg to 3.46 kg. Although the 7 brands of BIM provided slightly different estimates, the results of this study suggest that 5-BIM and M-BIM are relatively valid in human body composition.

A number of studies have shown that sleep disordered breathing (SDB) has a strong relation with obesity. The purpose of this study was to examine the effect of a short-term weight-loss program in obese men with SDB. In our 14-week weight-loss program, forty-one obese men (mean±SD, age ; 49.6±10.8 yr, body mass index ; 27.9±2.5 kg/m²) were assigned to 2 subgroups : diet only (DO ; n=19) and diet plus aerobic exercise (DE ; n=22). 2%, 3%, and 4% oxygen desaturation index (ODI) were measured by pulse oximetry before and after the weight-loss program. Weight and %fat significantly (p<0.05) decreased in the total subject pool consisting of DO plus DE (weight ; -8.4±3.5 kg, %fat ; -7.5±3.5%). 2%, 3%, and 4% ODI significantly decreased by -3.46±5.01 event/hour, -2.37±3.57 event/hour, and -1.99±2.84 event/hour, respectively. Significant correlations were found between 2%, 3%, and 4% ODI at baseline and changes of 2%, 3%, and 4% ODI during the weight-loss program (2% ODI ; r=0.48, 3% ODI ; r=0.51, 4% ODI ; r=0.67). Weight loss and %fat loss did not differ significantly between DO and DE (DO : -7.6±3.2 kg, -6.8±3.2%, DE : -9.2±3.7 kg, -8.1±3.7%). The increase in maximal oxygen uptake was slightly larger for DE (4.7±4.6 ml/kg/min) compared to DO (2.5±3.3 ml/kg/min), but there was no significant interaction. Changes of 2%, 3%, and 4% ODI did not differ significantly between groups. These results suggest that for obese men with SDB, the weight-loss program is an effective method, leading to improvement in SDB, although the combination of aerobic exercise to diet may not produce additional effects to SDB, compared with the diet only.

The purpose of this study was to investigate the accuracy of estimating human body composition changes using bioelectrical impedance (BI) methods during a weight-loss intervention. Subjects were forty-three obese men (age : 49.2±10.5 yr, BMI : 27.8±1.7 kg/m²) who completed a 14-week weight-loss intervention. In all subjects, fat mass (FM) and fat-free mass (FFM) were assessed by dual energy x-ray absorptiometry (DXA) as well as single- and multi-frequency BI methods (SBIM, MBIM) before and after the intervention. Resistance parameters were measured by SBIM and MBIM (SBIM : R₅₀ ; MBIM : R∞, R0, and Rfc). In nine subjects these variables were also measured at weeks 1 and 4. Weight decreased (P<0.05) by -8.0±3.2 kg during the intervention while FFM changes averaged -0.4±1.6 kg (DXA), -2.0±1.5 kg (SBIM), and -1.6±1.7 kg (MBIM). BI methods overestimated FFM before the intervention (before ; DXA : 54.4±4.8 kg, SBIM : 56.5±4.3 kg, MBIM : 55.9±4.5 kg). In nine subjects, FFM measured by SBIM (FFM_SBIM) and MBIM (FFM_MBIM) was similar to FFM measured by DXA(FFM_DXA)(after ; DXA : 54.6±5.4 kg, SBIM : 54.6±3.8 kg, MBIM : 54.6±4.1 kg), although BI methods overestimated the FFM before the intervention (before ; DXA : 54.9±5.1 kg, SBIM : 56.9±3.8 kg, MBIM : 56.3±4.4 kg). The ΔFM_SBIM and ΔFM_MBIM were highly correlated with the ΔFM_DXA(SBIM : r=0.87, MBIM : r=0.88). The ΔFFM_SBIM andΔFFM_MBIM were significantly correlated with the ΔFFM_DXA(SBIM : r=0.54, MBIM : r=0.49). The ΔR₅₀ and ΔRfc were also significantly correlated with the ΔFFM_DXA(R₅₀ : r=-0.63, Rfc : r=-0.48). These results suggest that during a weight-loss intervention, 1) BI methods and DXA provide similar estimates of human body composition change, although they overestimate FFM in obese men, and 2) changes of resistance parameters observed with BI methods may estimate human body composition change more accurately.

Purpose：The purpose of this study was to investigate the effects of change in daily physical activity during an exercise intervention on health status and physical fitness.Methods：Participants were 22 obese middle-aged men (BMI : 29.1±2.8 kg/m², 54.1±11.4 yr). They performed 90-min exercise sessions on a regular basis 3 days per week for 3 months. Physical activity (total energy expenditure, TEE ; activity energy expenditure, AEE ; and step counts) was measured using an accelerometer. Daily physical activity was defined as that which was performed outside of the exercise class. A 3-day food record was used to estimate energy intake. Results：Body weight decreased (-3.0±2.5 kg, P＜0.05). Vital age (VA), an index of comprehensive health status, and physical fitness age (PFA), an index of comprehensive physical fitness, significantly improved (VA : -8.7±5.5 yr, PFA : -8.5±5.1 yr, P＜0.05). Energy intake remained unchanged during the intervention (＋63.7±546.1 kcal/d). Daily physical activity increased (TEE : ＋83.0±130.1 kcal/d, AEE : ＋76.9±103.3 kcal/d, step counts : ＋1789±2819 steps/d, P＜0.05). Change in daily physical activity was correlated with change in VA (AEE : r＝-0.52, step counts : r＝-0.46, P＜0.05), while change in daily physical activity did not correlate with change in PFA. Conclusion：These results suggest that changes in daily physical activity during an exercise intervention are associated with improved health status.

The purpose of this study was to determine daily steps corresponding to the reference value for the quantity of Physical Activity and Exercise for Health Promotion 2006 (23 METs·h/wk) considering non-locomotive activities. Two hundred and thirty one men and 224 women wore a tri-axial accelerometer for two weeks. We analyzed the data in each age group (young (less than 40 years), middle-aged (40 to 59 years), and elderly (60 years or more) groups), also. There were significant relationships between daily steps and locomotive activity (r = 0.762 to 0.820, p < 0.001) and total (locomotive and non-locomotive) physical activity (r = 0.706 to 0.824, p < 0.001) with intensity of 3 METs or more in all groups. The daily steps corresponding to 23 METs·h/wk, calculated using regression lines between the daily steps and total physical activities with intensity of 3 METs or more in men and women were 6,534 steps/d and 6,119 steps/d. On the other hand, the daily steps corresponding to 23 METs·h/wk, calculated using regression lines between the daily steps and locomotive activities with intensity of 3 METs or more in men and women were 7,888 steps/d and 8,584 steps/d. These results suggest that non-locomotive activity should also be taken into consideration in the case of assessment of a daily physical activity.