Although regular physical activity has many beneficial health-related effects for the elderly, inappropriate or excessive exercise has been known to exaggerate or be associated with risk of cardiovascular events. Therefore, appropriate initial health screening, including medical evaluation and risk stratification, is vital to ensure or increase exercise safety.
In the elderly, medical evaluation needs to focus on identifying the coronary risk factors or signs suggestive of cardiovascular disease, since coronary artery disease has been demonstrated to be the most common cause responsible for cardiovascular events during physical activity in the elderly. It is noteworthy that variability of physical fitness is high in the elderly and cardiovascular risk during exercise is greater in subjects with lower physical fitness. In risk stratification, there-fore, pre-assessment of physical fitness in addition to routine medical evaluation is pivotal.
Exercise prescription must be based on risk stratification and/or complicating cardiovascular disease severity. Low-level exercise, for example, 40% of VO₂max is recommended for high-risk subjects such as those with two or more coronary risk factors, suggestive cardiovascular disease, lower physical fitness, or flail order adults. Since most subjects have reported at least one prodromal symptom within one week of sudden death, it is very important to check the physical condition before exercise on each day. Although various arrhythmias are likely to be responsible for cardiac events during exercise, their complete prediction is seldom possible. Therefore, monitoring EGG during exercise contributes greatly to exercise safety.
Further investigation is required for improvement of exercise safety for the 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.

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.

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.

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.

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.

We used near-infrared spectroscopy (NIRS) to study noninvasively the effects of aging on changes in muscle oxygenation during steady bicycle exercise. For the study, 6 healthy young males and 13 healthy elderly male volunteers were recruited. To evaluate the physical fitness level and to determine exercise intensity, the ventilatory threshold (VT) was first measured. As a result, elderly subjects were divided into two groups according to O₂ uptake at VT (Elderly-H ; 936.0±26.4, Elderly-L ; 695.3±29.9, Young ; 790.0±51.19 ml) . Secondly we measured muscle oxygenation by NIRS at rest and during exercise at relative work intensities of VT ; 20%, 40%, 60%, 80% and 100%. In all cases muscle oxygenation at rest and during exercise was expressed as a relative value from 100% oxygenation (oxygen capacity) established by thigh occlusion (ischemia) . All subjects showed progressive deoxygenation with increasing intensity. There were no differences between the three groups in muscle oxygenation during exercise at relative work intensity of VT. These data suggest that aging and physical fitness level have no effect on muscle oxygenation below relative work intensity of VT.

The effect of daily physical activity on oxidative stress is still an unknown issue, especially in middle-aged and elderly individuals. In this study, we examined the relationships of oxidative stress and antioxidant capacity with daily physical activity, taking into consideration the dietary antioxidant vitamin intake (vitamin B₂, C and E) of middle-aged and elderly people (66.0±7.0 years, n= 21; 10 males and 11 females, including 5 male trained runners) . Daily physical activity was measured using both a calorie counter and a questionnaire over a period of two weeks. The plasma concentration of thiobarbituric acid reactive substance ( [TBARS] ) and both oxidized and reduced glutathione concentrations ( [GSSG] and [GSH] ) in whole blood were determined in blood samples obtained at rest and immediately after two periods of acute exercise: maximal cycle ergometric exercise and steady state cycle exercise at 80% of ventilatory threshold (VT) for 30 minutes. At a given statistically controlled dietary antioxidant vitamin intake level (vitamin B₂, C and E), the amount of daily physical activity was associated with neither [TBARS], [GSH] and the ratio of [GSSG] / [GSH] at rest, nor changes in levels of these substances after both exercise tests. These data suggest that the amount of daily physical activity may have little influence on oxidative stress or antioxidant capacity at rest and after acute cycle ergometric exercise. Further investigation would be necessary to clarify how much volume or intensity of physical activity induces increased oxidative stress, from the aspect of habitual physical training and nutrition.

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.