The aim of the study was to measure the cross-sectional area of the psoas major muscle (P-ACSA) in high school athletes and to produce a P-ACSA index independent of body size using an allometric modeling approach to examine the differences in gender and sport specialization. The subjects were 254 female (16.8±0.8 yrs) and 540 male (16.9±0.8 yrs) high-level high school athletes from 17 different sports. Fat-free mass (FFM) was measured by the Bod Pod system (LMI) and P-ACSA was determined by magnetic resonance imaging at the center of the L4-L5 transverse level. Since the power function model fit the data better than a simple linear model in the correlation between FFM and P-ACSA, and the power exponent parameter was almost equal to the theoretically anticipated 2/3 in both genders, the P-ACSA per FFM^2/3 as well as the absolute P-ACSA was calculated. Both of the absolute P-ACSA and P-ACSA per FFM^2/3 were significantly different according to gender and the sport specialization. While volleyball and badminton players and canoeists showed smaller P-ACSA, in accordance with the previous studies on senior sprinters, high school sprinters also showed predominant development of P-ACSA regardless of gender. These results suggested that regular involvement in sprinting activity could affect the size of the psoas major muscle in high school athletes.

Objectives : The present study investigates the effects of body iron stores upon indices of biosynthesis and destruction of red blood cells (RBC) induced by a single session of cycling exercise.
Design : Eight sedentary female students were divided into groups depending on their body iron stores : normal (C group, n=5) and iron deficient (D group, n=3) . Blood samples were collected at five time points of before (pre), immediately after (0 hours), then 1, 3 and 6 hours after exercise (248±31 kcal, 70% V0₂ peak level) . Osmotic fragility and serum haptoglobin (hp) concentration served as of for degradation, and δ-aminolevulinate dehydratase (ALAD) activity, erythropoietin concentration and number of reticulocytes served as indices of RBC biosynthesis.
Results : A single session of cycling exercise did not affect the level of RBC, hemoglobin, hematocrit, serum iron, ferritin, transferrin saturation, hp and osmotic fragility in either groups. The δ-ALAD activity increased at 3 (p<0.05) and 6 hours (p<0.01) after exercise compared with that at 0 hours in the C group. In contrast, δ -ALAD activity in the D group was significantly lower at 3 hours after exercise than that of C group (p<0.001) . Reticulocytes and erythropoietin concentration increased gradually in the C group after exercise, but not in the D group.
Conclusions : A single session of cycling exercise under our experimental conditions enhanced RBC biosynthesis indicated by δ -ALAD activity, whereas exercise-induced hemolysis was not evident. Body iron stores affect the δ -ALAD activity induced by a single bout of cycling exercise.

OBJECTIVE: To analyze whether sufficient energy intake (EI) improves performance of activities of daily living (ADL) in patients with hip fracture admitted to rehabilitation hospitals. The adequate amount of EI for improving performance of ADL in patients with hip fracture remains unknown. METHODS: This retrospective cohort study included all patients with hip fracture (n=234) admitted to rehabilitation hospitals in Japan. The inclusion criteria for this study were age >65 years and body mass index <30.0 kg/m². Patients who were transferred to an acute hospital and those with missing case data were excluded. According to the amount of EI, the patients were classified into energy sufficiency and shortage groups (EI/total energy expenditure ≥1.0 and <1.0, respectively). The Functional Independence Measure (FIM) and FIM gain were used to evaluate the patient disability level and change in patient status in response to rehabilitation. Finally, FIM gain was calculated as the discharge FIM score minus the admission FIM score. RESULTS: The final analysis targeted 202 patients—53 (26.2%) were in the energy shortage group and 149 (73.8%) were in the energy sufficiency group. The energy sufficiency group had a greater FIM gain than the energy shortage group (mean, 25.1±14.2 vs. 19.7±16.4; p=0.024). Furthermore, sufficient EI in the first week since admission (β=0.165; 95% confidence interval, 0.392–5.230; p=0.023) was an independent factor of FIM gain. CONCLUSION: Among elderly patients with hip fracture admitted to rehabilitation hospitals in Japan, the amount of EI during the first week after admission was an independent factor of FIM gain.
Activities of Daily Living ; Aged ; Body Mass Index ; Cohort Studies ; Energy Intake ; Energy Metabolism ; Femoral Fractures ; Hip ; Humans ; Japan ; Nutritional Support ; Recovery of Function ; Rehabilitation ; Retrospective Studies