Objective: Aerobic exercise on land decreases arterial stiffness, however, the effect of exercise in water on arterial stiffness has not been clear. This study investigated the effect of a 15-min cycling exercise on land and that in water on pulse wave velocity (PWV) as an index of arterial stiffness. Methods: Nine healthy young men were randomly performed exercise on land and exercise in water equivalent to 50% of each maximum oxygen uptake on separate days. The PWV from carotid to femoral artery (aortic PWV) and femoral to posterior tibial artery (leg PWV) were measured at baseline and 15, 30, 60 min after exercise. Results: The heart rate in water was significantly lower during exercise than that on land. In addition, the carbon dioxide output and respiratory exchange ratio during exercise were significantly greater in water. Body temperature increased after the exercise on land but decreased after the exercise in water. Although the aortic PWV and leg PWV decreased concomitantly with decrease in SBP and DBP after the exercise on land, there were no significant changes after the exercise in water. Conclusion: Although acute exercise on land decreased arterial stiffness after exercise, acute exercise in water of the same exercise load did not. The differences in body temperature and blood pressure after exercise may result in diverse arterial stiffness after exercise.

Objective: To assess LV function during and after warm-water immersion in elderly subjects. Concomitantly with aging, left ventricular (LV) diastolic function decreases. According to results of previous studies, warm-water immersion improves cardiac function in patients with cardiovascular disease. However, its effect in normal elderly is still unclear. Material and Methods: To investigate the effect of acute warm-water immersion on LV function with Doppler echocardiography in elderly subjects, subjects underwent immersion in 40°C water to nipple level for 15 min. Results: The stroke volume (SV), cardiac output (CO), and LV ejection fraction (LVEF) increased significantly during and after warm-water immersion. The ratio of early diastolic mitral inflow (E) and early diastolic mitral annular tissue velocity (E’), an index LV of filling pressure, did not increase during or after immersion. Some LV diastolic function indexes such as E increased during immersion, but after immersion indexes of diastolic function were not different relative to before immersion. Conclusion: These results suggest that LV diastolic function did not correspond to the increased systolic function in elderly subjects, so it might suggest that the LV contraction-relaxation coupling may be interrupted in elderly.

The number of sudden deaths occurring during bathing in Japan has recently exceeded 10, 000 people and the 80% of these have occurred to the elderly. Although some guidelines for safe bathing are available, bathing-related accidents have still not declined. The purpose of this study is to use a questionnaire to survey the daily bathing habits of middle-aged and elderly people.
Method: For the subjects of this study, 77 middle-aged and elderly persons attending a healthful exercise class were given a questionnaire survey, and of these 10 persons were recruited at random and their daily bathing habits at home were studied. Results: The questionnaire survey revealed that almost all of the middle-aged and elderly people had unsafe bathing habits. In addition, a comparison of the questionnaire and the home habits study showed much discrepancy between the perceived and measured body and room temperatures before, during, and after bathing. Conclusion: Almost all middle-aged or elderly people had unsafe bathing habits.

High-sensitivity C-reactive protein (CRP) is a novel risk factor for coronary artery disease. It is well known that body weight loss is effective in reducing serum CRP concentration ; however, the effect of exercise training on serum CRP concentration has not been fully elucidated. The purpose of this study was to examine the effect of a 24-week exercise training program on serum CRP concentration in 169 healthy middle-aged and elderly subjects (65.9±6.4 years). Each subject underwent baseline testing (peak oxygen uptake, daily physical activity, body weight, and serum CRP levels), and repeated these tests on completion of the training program. The subjects were classified into 2 groups based on initial CRP levels : normal<1.0 mg/L, n=139, and high≥1.0mg/L, n=30. On completion of the program, both daily physical activity and peak oxygen uptake increased significantly (+33.9±72.4%, p<0.0001, +5.4±14.7%, p=0.014, respectively). However, body weight did not change significantly. In addition, CRP levels of the entire group did not change significantly. However, CRP levels significantly decreased among the high baseline CRP group (from 1.82±0.81 mg/L to 0.98±0.59 mg/L, p<0.0001). It was concluded that serum CRP levels are reduced without body weight loss in response to exercise training in healthy middle-aged and elderly subjects with high initial CRP levels.

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.

To investigate a relationship between gender differences in recovery from skeletal muscle fatigue and muscle oxygenation, we examined whether there is a difference in oxygen supply and consumption of the working muscles after intermittent handgrip exercise between young males and females using near-infrared spectroscopy (NIRS). Healthy young subjects (25.8±3.9 years ; males, n=10 ; females, n=10) repeated static maximal voluntary contractions (MVC) with a handgrip for 5 seconds followed by 5 seconds rest for a period of 4 minutes in Study 1. The MVC force was measured before, each minute during the handgrip exercise, and 2, 5, and 10 minutes following the exercise. In Study 2, the selected 10 subjects (males, n=5 ; females, n=5) performed the same exercise and their total- and deoxy- hemoglobin/myoglobin level was measured using the venous occlusion NIRS method; and O₂ supply index (OSI) and O₂ consumption index (OCI) calculated before and after the exercise. In Study 1, females exhibited higher %MVC force at the end of the exercise and during the recovery period than males (p<0.05). In Study 2, the %OSI was significantly lower in females than in males at 5 and 10 minutes in the recovery period (p<0.05), but no significant differences were detected in %OCI. Furthermore, %MVC of the recovery period correlated with %OCI of the recovery period in females (r=0.724, p=0.015), but not in males. These findings suggest that female working muscles can convert consumed oxygen more effectively after an intermittent handgrip exercise, and therefore, be able to recover muscle force faster.

Resistance exercise in the elderly and patients with a cardiovascular disorder has been thought to have a high cardiovascular risk, because it has the tendency to cause an excessive rise in blood pressure and induce serious arrhythmia. But recently, resistance exercise has been introduced into physical therapy because the safety of such exercise has been confirmed in subjects without a cardiovascular disorder.
The purpose of this study was to investigate the safety of lower extremity resistance exercise in middle-aged or elderly subjects with hypertension and receiving medical treatment (n=24), and those without hypertension (n=40), by measuring cardiovascular response during resistance exercise of different loads (40% and 60% 1 RM), and usefulness of respiratory guidance during such exercise.
As a result, there was no difference in diastolic blood pressure between those with and without hypertension ; but systolic blood pressure and rate pressure product both at rest and during exercise were significantly greater in patients with hypertension. However, neither group showed symptoms of angina, ischemic signs in ECG, or serious arrhythmia ; and there was no difference in the frequency of excessive rise in blood pressure between the groups (2 subjects with hypertension and 1 subject without hypertension) . Blood pressure during exercise was significantly lowered by respiratory guidance.
These results show that it is important to measure blood pressure during exercise before resistance exercise training regardless of the presence of hypertension, although an excessive rise in blood pressure occurred in only a few subjects. Furthermore, it is important to exhale slowly and not hold one's breath during exercise.

Arterial compliance progressively decreases with aging. This aging-induced reduction of arterial compliance causes an increase of systolic blood pressure (SBP), whereas regular exercise increases arterial compliance. We hypothesized that an increase in daily physical activity (DPA) produces a beneficial effect on systemic arterial compliance (SAC ; an index of central arterial compliance) and this phenomenon could decrease SBP in the elderly. We investigated the relationship among DPA, SAC, SBP, diastolic blood pressure (DBP), and some other risk factors for cardiovascular and/or cerebrovascular events (total cholesterol, HDL-cholesterol, and HOMA-R) cross-sectionally in 127 elderly persons (42 male, 85 female : aged 74±4 years) . The DPA was estimated by expended calories using an accelerometer. The SAC was calculated from a finger pulse pressure waveform recorded by using PORTAPRES ; and stroke volume obtained from the same pressure waveform based on the volume-clump method. The analyses demonstrated that SBP was directly and decreasingly affected by SAC, and that DPA had an increasing effect on SAC. Furthermore, SBP was directly and increasingly affected by DBP, and DBP was directly and decreasingly affected by both SAC and DPA. Therefore, it is considered that DPA may have suppressive effects on the rise of SBP through the indirect effects of changing SAC and DBP. These findings suggest that an increase in DPA could improve the age-induced reduction of arterial compliance and rise of SBP in elderly humans.

The purpose of this research was to study the effects of exercise program participation on the personal factors of exercise adherence promotion in the middle-aged and elderly by comparing a group and individual exercise program. The personal factors for promoting exercise adherence, the four domains (i, e. initiative attitude, achievement satisfaction, self-recognition, and intrinsic motivation), were hypothesized. Two groups of middle-aged and elderly subjects, who volunteered to participate in different 6-month exercise programs, were examined. Group 1, 33 subjects (aged 67.7 ±4.3 years : mean±SD), participated in a program consisting of an individual exercise program (combination of endurance and resistance exercise, e. g. cycling exercise, dumbbell and machine exercise, once a week) and group exercise program (e, g. dance and ball game, once a week) . Group 2, 27 subjects (aged 65.2±4.Ovears), participated in the same individual exercise program twice a week. After the 6-month exercise program, significant improvements in group 1 were found in the selfassessment of activity score of the initiative attitude domain, the achievement satisfaction score including enjoyment, achievement and satisfaction, and the self-recognition score representing competence. In group 2, the mastery score in the intrinsic motivation domain was reduced, and the curiosity score in the same domain and the achievement score in the achievement satisfaction domain tended to decrease. These results show that a group program might have a more significant effect on the personal factors hypothesized to promote exercise adherence in this study. Hut there should be follow-up study on the subjects to determine the effectiveness of the program over the long term.