ABSTRACT
Purpose : Rhythmic gymnasts sometimes develop severe iron-deficiency anemia. Preventing such anemia could thus enhance both their performance and health. We compared the relationship between a dietary intervention and RBC metabolism.Methods : Ten female rhythmic gymnasts were recruited for this study. Changes in the RBC delta-aminolevulinate dehydratase (δ-ALAD) activity were used as an index of biosynthesis, and changes in the haptoglobin (hp) were used to assess degradation.Results : During the one month intervention period, the athletes consumed traditional Japanese foods which provide 1500 kcal energy, 2 g/kg body weight protein, 200 g carbohydrate and 15 mg iron. No main effect of this intervention on the hematological indexes was observed. The δ-ALAD activity was significantly greater in August than in July or September. Hp concentration was significantly lower in August in comparison to the other periods.Conclusion : Dietary intervention might enhance the RBC turnover by increasing the capacity for erythrocyte biosynthesis and degradation.
ABSTRACT
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.
ABSTRACT
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.