The present study was performed to investigate heart rate responses and occurrence of arrhythmias caused by various diving maneuvers and swimming in infants. Forty four healthy infants (mean age 2.5±1.1, mean ±SD) served on this study. Condition of telemetry electrocardiograph recording was 1) rest on the land and in the water, 2) diving, 3) swimming and 4) “pass in water (PW) ”. Moreover, diving styles was classified for five patterns by presence of body movement or expiration (Apneic not move diving, Expiratory not move diving, Apneic kick diving. Expiratory kick diving and Underwater swimming) . “Diving bradycardia” was observed during diving and PW, and the magnitude of heart rate reduction was grater in diving without body movement than diving combined with body movement. Presence of expiration did not influence on the level of bradycardia during diving. Any kinds of arrythmias was observed 13 out of 44 subjects. In premature contractions, supraventricular premature contraction (SVPC, 7 subjects) was observed more often than ventricu-lar premature contraction (PVC, 3 subjects) . Another arrhythmias observed was atrioventricular junctional rhythm (AVJR, 1 subject), atrioventricular junctional escaped beat (AVJEB, 3 subjects) and wandering pacemaker (1 subject) . The danger arrhythmias which is necessary to restrict on exercise or swimming was not observed in this study.

The purpose of this study was to investigate the effects of running training on bone formation in rats in relation to the age training started. The first experimental period was set from 6 to 12 weeks (wks) old and the second from 12 to 19 wks old. Sixty-four Wistar strain 6-wk-old male rats were initially divided into a non-exercise (N) and an exercise (E) group. At 12 wks old, each group was subdivided into two groups, providing four groups: non-exercise·non-exercise (NN), non-exercise·exercise (NE), exercise·non-exercise (EN) and exercise·exercise (EE) . Exercise consisted of treadmill running at a speed of 30 m/min, 60 mm day, 5 days wk. The animals were sacrificed before the experiment (6 wks old), post-first experiment (12wks old) and postexperiment (19 wks old), the bilateral tibiae were removed and their lengths, bone mineral content (BMC), bone mineral density (BMD) and bone histomorphometric parameters were measured. The tibial length was significantly shorter in 12-wk-old E than N rats and in 19-wk-old EE than NN. At 19 wks old, the total tibial BMD values were significantly higher in EE than NN, and the BMD values of the proximal and distal tibiae, where the cancellous bone was the main component, had increased markedly, whereas no differences between the diaphyseal BMD of each group were noted. Bone histomorphometry at 12 wks old, considered the immature period, showed that the osteoid surfaces and labeled surfaces tended to be increased by running training, but the bone volume was unchanged. In contrast, at 19 wks old, considered the early mature period, the osteoid surfaces showed a tendency to decrease and labeled surfaces to increase and consequently the bone volume increased albeit not significantly. These results suggest that: 1) running training started in immature rats represses longitudinal tibial growth, 2) the cancellous bone is more sensitive then the cortical bone to this type of training and 3) training of early mature rats increases bone volume by increasing the efficiency of osteoid calcification.

To investigate the influence of long-distance running on bone metabolism, we measured bone metabolism markers in eight healthy young men before and 4 months after the start of training program of 10 km running. Measurements were then taken the day before a marathon race, immediately after, and 1 day, 2 days and 5 days after.
As a result of exercise, the levels of serum osteocalcin (OC), a bone formation marker, and urinary deoxypyridinolin (D-Pyr), a bone resorption marker, decreased significantly. After the marathon race, the OC level decreased further corresponding to an increase of hydrocortisone right after the race. However, from the day following the race, the OC level showed a slight increase. D-Pyr showed an increasing tendency immediately after the race, and the levels of OC and D-Pyr increased significantly 5 days after the race.
Bone formation and resorption decreased as a result of light, low-frequency endurance exercise. However, both of them increased after intense physical stress. From this result, it is suggested that the intensity and frequency of exercise affect bone metabolism differently, even though the type of exercise load is similar.

‹Objective› In previous animal studies, it has been observed that ovarian hormones centrally alter baroreflex modulation of cardiovagal nervous control. If this central action of ovarian hormones is observed in human females, non-baroreflex modulation of cardiovagal nervous control should change with the menstrual cycle. The hypothesis in this study was that cardiovagal nervous response to facial cold stimuli (non-baroreflex modulation) changes throughout menstrual cycle.‹Subjects and methods› Eight young healthy women with a normal menstrual cycle participated in this study. The menstrual cycle was divided into 5 phases (menstrual, follicular, ovulatory, early luteal and late luteal) . Resing ECG RR intervals, cardiovagal nervous activity (by heart rate variability), RR intervals and cardiovagal nervous response to facial cold stimuli were measured during each menstrual phase. RR intervals and cardiovagal nervous response to facial cold stimuli were evaluated paying attention to the “quantity” and “quickness” of the changes.‹Results› There were no phase differences in resting RR intervals and cardiovagal nervous activity. Quantity of RR intervals and cardiovagal nervous response and quickness of. RR intervals to facial cold stimuli did not change throughout the menstrual cycle. The speed of cardiovagal nervous response to facial cold accelerated in the follicular phase, and to the contrary, slowed down in the early luteal phase, ‹Conclusion› These data suggest the speed of cardiovagal nervous response mediated non-baroreflex mechanism changes throughout the menstrual cycle.

The form and electromyographic pattern of archery shooting were compared between experts and amatures. Using methods are electromyography, photography and X-ray photography.
In the expert group, the shoulder joint of the pushing arm is in neutral position of rotation and the forearm is in supinated position. In the amature group the shoulder joint is in externally rotated and forearm is pronated. The delta muscle provides more powerful abduction of the shoulder in neutral position of rotation.
The different discharge pattern of shoulder girdle muscles between two groups suggests that fixation of the bow is essentially important from release to follow-through.

Physical activity in the growing period has been shown to be effective for increasing bone mass because immature bones are more sensitive than mature adult bones to the stimulation with mechanical stress. However, bone growth is not uniform and changes markedly at puberty. Therefore, the response of bone to exercise may differ according to the growth process. The purpose of the present study was to investigate the process of the bone response to running training, and the relationship between the bone response and serum insulin-like growth factor-I (IGF-I) and IGF binding protein-3 (IGFBP-3) levels in female rats. Thirty-three female Wistar-Imamichi rats 4 weeks of age were divided randomly into control (CON) and running training (RUN) groups for 6 and 12 weeks. Training consisted of running on a flatbed treadmill at 30 m/min for 60 min/day, 5 days/week. The bone mineral content (BMC) and bone mineral density (BMD) in the whole and five parts of the tibia were measured by a dual-energy X-ray absorptiometer (DXA) . Simultaneously, we measured serum concentrations of IGF-I, IGFBP-3, osteocalcin and 17β-estradiol. The whole tibial BMD was significantly higher in the RUN groups than in the age-matched CON groups. When BMD was analyzed at five different studied parts within the same tibia, the increase of BMD. was noted in the proximal and distal cancellous bone in the 6-week RUN group, and in the diaphysial, cortical bone, in the 12-week RUN group. Serum concentrations of osteocalcin, a marker of bone formation, were not altered by training, whereas they decreased with aging. Serum IGF-I levels in the training groups were not changed, but IGFBP-3 levels were increased significantly only in 6-week RUN rats. As a complex between IGFBP-3 and IGF-I may be more improve than free IGF-I in the bone formation, the high levels of IGFBP-3 in the 6-week RUN group may induce an increase in the activity of IGF-I. There was a significant positive relationship between serum IGF-I concentration and BMD of the whole tibia in the 6-week study, and between the IGFBP-3 level and BMD in both the 6 and 12-week studies.
In conclusion, 1) the process of the skeletal response to running training is site-specific within the same bone, and 2) the increment of the IGFBP-3 level with training in the growth period may reflect the increment of tibial BMD through training.

Bone (tibia, femur, and lumbar spine) and blood samples were obtained from 100 (50 males and 50 females) Wistar-Imamichi rats in groups aged 3, 5, 7, 9, 12, 15 and 20 weeks old to investigate the changes in bone mass during puberty in relation to insulin-like growth factor 1 (IGF-1), IGF binding protein (IGFBP) -3, osteocalcin (OC) and sex steroids in normal rats.
Sharp increases in BMD (bone mineral density) in the tibia, femur and lumbar appeared earlier in female than in male rats, and the BMD in females tended to be higher than in males between 5 and 9 weeks old. After 9 weeks old, BMD in males was higher than that in females, as BMD in males continued to increase whereas that in females tended to remain in a steady state after this stage. This sex-related difference in changes in BMD pattern is probably related to the serum concentrations of IGF-1, IGFBP-3, testosterone, and 17β-estradiol with maturation. In males, marked increases in serum IGF-1 and IGFBP-3 concentrations appeared earlier than that in serum testosterone level. IGF-1 and testosterone peaked at 9 weeks of age, and thereafter remarked in a steady state, whereas IGFBP-3 reached a peak at 7 weeks of age, and then declined gradually. In females, the changes in patterns of serum 17β-estradiol, IGF-1, and IGFBP-3 levels were very similar. The levels increased gradually from 3-5 weeks old, peaked at 9 weeks, and then decreased slowly thereafter. In contrast, serum OC concentrations remain relatively high from 3 to 9 and from 3 to 7 weeks old in males and females, respectively, although OC in both sexes declined gradually with aging.
These observations suggest that BMD development occurs earlier in female than in male rats. This sex-related difference in changes in the BMD pattern may result from the earlier onset of puberty in females, and from the sex-specific differences in concentrations of IGF-1, IGFBP-3 and sex steroids with maturation.

The engaging>30 minutes of physical activity (PA) at 4-6 METs has been recommended for the prevention of cardiovascular disease. We determined whether relatively low intensity (i. e., 3-5 METs) PA inhibits the age-related central arterial stiffening, a risk of cardiovascular disease. In the cross-sectional study, the association between carotid arterial properties (via ultrasound system) and daily PA (via electric accelerometer) were studied in 172 normotensive people (41-82 yrs). People engaging>30 min/day of PA corresponding to 3-5 METs had a significantly lower beta-stiffness index than sedentary peers after adjusting for covariates (i. e., age and PA time at more than 6 METs). In the interventional study, beta-stiffness index of nine normotensive postmenopausal women was significantly decreased after the 12-week aerobic training (cycling at 80% of ventiratory threshold, ≈4 METs, 30 min/day, 5 days/week). These results suggest that the increase in daily PA at 3-5 METs inhibits the age-related carotid arterial stiffening.

Background/Purpose: Previous studies have suggested that environmental factors, such as weather, atmospheric temperature, humidity and seasonal change, may affect the disease activity of rheumatoid arthritis (RA). In the present study, we aimed to determine whether RA disease activity, including patient’s global assessment (PtGA), is influenced by seasonal variation, using a nationwide Japanese cohort database, NinJa (National Database of Rheumatic Diseases by iR-net in Japan). Methods: RA patients, who were registered in NinJa, are evaluated at any point during the indicated year. We analyzed data from RA patients (n=8,726), whose PtGA, pain visual analog scale (VAS) and physician’s global assessment (PhGA) data were available in NinJa 2012. In the present study, spring was defined as from March to May, summer as from June to November, Fall as from September to November and winter as from December to February. Age, sex, disease duration, number of tender joints, swollen joints, pain VAS, PtGA, PhGA, ESR, CRP, stage, class and mHAQ were also included as explanatory variables. Results: Univariable analysis using NinJa 2012 database revealed that PtGA, pain VAS and disease activity score (DAS)-28 were lowest during the fall months with statistical significance, which was reproducible in NinJa 2011 database analysis. On the other hand, multivariate analysis revealed that pain VAS, mHAQ and the number of swollen joints were the main determinants of PtGA, and seasonal variation was not identified as a statistically significant factor. Conclusion: We have clearly demonstrated that PtGA was lowest in fall. Seasonal changes can thus affect RA, although to a lesser degree than pain and activity of daily living, which should be taken into account when examining RA patients to better understand their symptoms.