The purpose of this study was to elucidate the changes in systolic and diastolic time intervals which accrue along with increase of HR during a prolonged exercise.
Fifteen male collegiate distance runners performed bicycle ergometer exercise of 70% maximal oxygen intake for 60 minutes. Electrocardiogram, phonocardiogram, pulse wave using ear densitogram and its derivative were recorded throughout the exercise, and then HR, STI, DT (diastolic time) and QS₂/DT were caluculated from the tracings.
The results obtained are as follows:
1. At the initial phase of the exercise, DT decreased markedly to result in rapid increase of QS₂/DT. When HR was between 130-150 beats/min, however, the rate of decrease of QS₂ was greater than that of DT, so QS₂/DT showed a tendency to decrease. When HR was more than 150, QS₂ reached a plateau but DT still continued to decrease, and QS₂/DT turned to increase again.
2. LVET decreased slowly throughout the exercise, whereas PEP decreased rapidly within initial two minutes and kept a steady state thereafter. The change in QS₂ after two minutes of exercise seemed to depend on LVET.
3. LVETi and QS₂i showed a similar change as that in QS₂/DT but the change in QS₂i was less obvious than that in LVETi.
4. PEN and PEP/LVET decreased rapidly in the initial two minutes, thereafter they continued to increase more slowly with increase of HR until the end of exercise.
Conclusively, HR continued to increase monotonously during prolonged exercise of a constant intensity, while systolic and diastolic time intervals varied the directions and patterns of their changes during the exercise.

A study was undertaken to determine whether the specific change in the ratio of systolic to diastolic time (QS₂/DT) observed during prolonged exercise¹⁷⁾ is dependent on HR or elapsed time, and also to elucidate the possible relationship between change in QS₂/DT and distance-running performance. Twelve male distance runners were divided into two groups, a high- (HP Group) and a low-performance (LP Group) group, according to their 10, 000-meter running performance. They performed 60-min exercise on a bicycle ergometer at a work load controlled so as to keep the HR at 150 bpm. HR, systolic time intervals (STIs) and DT were calculated from electrocardiogram, phonocardiogram and the derivative of ear densitogram.
In the time course of QS₂/DT, two crests were formed at 2 and 15 min after the start of exercise, and also two troughs were formed at 10 and 20 min. Some of these troughs and crests formed even when HR was kept constant. Patterns of change in QS₂, DT, QS₂/DT and other parameters were similar in the two groups. However, the absolute values of the parameters differed. QS₂, left ventricular ejection time (LVET) and QS₂/DT in the HP Group were lower than those in the LP Group, whereas DT in the HP Group was longer than that in the LP Group.
From these findings, it was concluded that the specific change seen in QS₂/DT during prolonged exercise is dependent not on the HR level but on elapsed time. The changes in STIs and DT during prolonged exercise are thus influenced by the distance-running performance of the subjects.

It was the purpose of this study to examine the property of skeletal muscle fiber in middle- and long-distance runners, and to evaluate the relationship between the property of skeletal muscle fiber and aerobic work capacity.
Biopsy samples were taken from M, vastus lateralis of 23 middle- and long-distance runners, and analyzed for muscle fiber composition, capillary supply and SDH activity. Aerobic work capacity was measured on a treadmill with continuous method.
The mean value for % ST in M. vastus lateralis was 61.3%, and the muscle fiber distribution showed the tendency of slow type. The crosssectional area of ST and FT fibers ranged approximately from 3, 000 μm² to 13, 000 μm², and the cross-sectional area of ST fiber tended to be larger than that of FT fiber. The mean values for CD, C/F ratio, and CC (/ST) as capillary supply were 279/mm², 1.62 and 5.7, respectively. The mean value for SDH activity was 5.86 μmoles/g/min, and was lower than reported previously for elite runners. In addition, SDH activity correlated with % ST and CC (/ST) (r=0.480, p<0.05, r=0.640, p<0.01) . On the other hand, the mean value for VOG₂max was 68.5 ml/ kg/min (4, 066 ml/min), while VO₂@AT averaged 45.9 ml/kg/min (2, 756 ml/min) . And it was found that VO₂max and VO₂@AT correlated significantly with % ST, CC (/ST) and SDH activity. Particular, VO₂ max was most strongly related to SDH activity (r=0.612, p<0.01) .
The results of this study suggest that in regard to middle- and long-distance runners, structural characteristics of the ST fiber and capillary are some of the indispensable factors to regulate such a functional property as SDH activity and that the distinctive characteristics of the skeletal muscle fiber might possibly influence aerobic work capacity to a great extent.

School lunches serve to improve nutritional status and to promote the health of children. The purpose of this study was to investigate the portion sizes of school lunches served and consumed in Japanese elementary schools. In addition, gender difference in servings and consumption were also studied. A cross-sectional study was undertaken between October 2007 and February 2008 in schools located in Tokyo and Okayama, Japan. A total of 192 fifth-grade children attending four elementary schools participated in this study. Weighed plate waste methods and observation were used to collect dietary data for two non-consecutive days. The proportion of children who chose staple foods along with main dishes and/or side dishes for at least one day was higher in boys than in girls (respectively, for staple food: 42.1% vs. 9.3%, for main dish and/or side dish: 68.4% vs. 44.3%, P < 0.001). The ratio of initial amount served to amount offered was 0.88 +/- 0.11 for boys and 0.84 +/- 0.10 for girls (P < 0.05). The ratio of amount consumed to amount offered was 1.04 +/- 0.19 for boys and 0.88 +/- 0.12 for girls (P < 0.001). Weight was related to amount consumed both in boys (r = 0.222, P < 0.05) and in girls (r = 0.201, P < 0.05). These findings suggest that the nutritional standards of school lunch programs should take into account gender differences. Clearly, boys were more likely to consume more than the initial amounts served due to their higher propensity to take second helpings. Boys feel few reservations about taking second helpings to adjust their total intake. However, school lunch plans should take into consideration girls' reluctance to do so, by serving appropriate initial portion sizes.
Asian Continental Ancestry Group ; Child ; Cross-Sectional Studies ; Humans ; Japan ; Lunch ; Nutritional Status ; Tokyo

OBJECTIVES: The purpose of this study is to evaluate the efficacy of annual zoledronic acid treatment in Japanese patients with nonmetastatic prostate cancer during androgen deprivation therapy (ADT). METHODS: This is a single institution 12-month study. Between 2016 and 2019, patients aged 70 years or older on ADT for nonmetastatic prostate cancer had bone mineral density (BMD) measured and 10-year probability of fracture calculated using fracture risk assessment tool (FRAX). Patients who showed osteopenia or had a 10-year hip fracture risk ≥ 3% or a 10-year probability of major osteoporotic fracture ≥ 20% were offered treatment with zoledronic acid 5 mg intravenously (ZA group). The patients who did not receive treatment were set as the control group. Lumbar and hip BMD were measured 6 and 12 months after treatment in the ZA group and 12 months after baseline in the control group. The yearly BMD change of both groups was compared. RESULTS: The mean ages of the ZA group (n = 26) and control group (n = 12) were 80.5 ± 9.1 and 76.1 ± 6.7 years, respectively. In the ZA group, lumbar and hip BMD changes at 12 months were +2.1% and +0.8%, respectively. In the control group, lumbar and hip BMD changes were −0.9% and −4.9%, respectively. There were statistically significant differences between the 2 groups in BMD percent changes (P < 0.05). CONCLUSIONS Without intervention, BMD tends to continue to decrease during ADT. Our findings suggest that administration of zoledronic acid enables maintenance of BMD in the older adults.