AEROBIC CAPACITY AND THE METHOD TO EVALUATE IT IN COMMUNITY DWELLING ELDERLY / 体力科学

The purpose of this study is to discuss the effects of aging and exercise on aerobic capacity in the elderly and the procedure for encouraging sedentary elderly to engage in a health promotion program based on aerobic exercise. Regular proper aerobic exercise training, even when started as an elder, induces an increase in maximal oxygen intake and lactate threshold (or ventilatory threshold) by enhancing ventricular diastolic function and oxidative capacity in muscle ; and reduces the risk factors of lifestyle related diseases. There was a need for a simple test for determining aerobic capacity and exercise prescriptions in community-dwelling elderly. We recommended two methods for this purpose : one is to determine DPBP and the other is to estimate work rate at a certain concentration (rest plus 0.1 mmol /l ) of the blood lactate based on it just after 2 A stage step exercise. Both work rate can be used not only for evaluation of the aerobic fitness level, but also a safer and effective exercise intensity to elucidate the benefit of aerobic exercise. These tests were very simple and can determine 5 to 10 people simultaneously.

Relationship between thermoregulation and cold-induced vasodilation during cold exposure with regard to maximal oxygen intake / 体力科学

Based on the maximal oxygen intake (VO<SUB>2</SUB>max), 24 male students were classified into high (H-G), middle (M-G) and low (L-G) groups of the VO<SUB>2</SUB>max level. In each VO<SUB>2</SUB>max level group, thermoregulation characteristic values during cold exposure at an ambient temperature (Ta) of 12°C were compared with several parameters of cold-induced vasodilation (CIVD) measured at 28°C (observation 1) and the parameters measured after 30 min from the start of 60-min cold exposure (observation 2) . The relationship between CIVD as a peripheral vasomotor regulation response, and autonomic thermoregulatory response was examined. The results are as follows:<BR>A . H-G showed the smallest decreases in the rectal temperature (Tre) and in mean skin temperature (Tsk), and these parameters decreased as VO<SUB>2</SUB>max decreased. Enhancement of metabolic heat production (M) was highest in H-G and lowest in L-G.<BR>B . In the observations 1 and 2 of the CIVD tests, mean skin temperature (MST), temperature at first rise (TFR) and resistance index (RI) increased with rise in VO<SUB>2</SUB>max, while time of temperature rise (TTR) decreased. In the observation 2, TFR remained low by decreased temperature before water immersion (TBI) and, with TBI taken into consideration, no significant change in RI was observed except only in L-G.<BR>C. MST, TTR and RI in the CIVD measurements (observation 1 and 2) were significantly correlated with the mean thermoregulation characteristic value during 30-60 min after the start of cold exposure (the second half period) .<BR>D. During the second half period of cold exposure, significant negative correlations were observed between Tsk and body fat% (BF%) and between M and BF %. VO<SUB>2</SUB>max was significantly correlated with RI, Tre, Tsk and M.<BR>These results indicate that difference in physical fitness for endurance is clearly reflected in the values of cold-induced vasodilation in thermoneutral zone and during cold exposure. The peripheral vascular resistance of finger increased during cold exposure from that in thermoneutral zone causing decrease of finger skin temperature. After that, due to hunting reaction, the peripheral vascular resistance decreased, and a correspondance was observed between effectiveness in raising finger skin temperature through increase in skin blood flow and physical fitness for endurance. An interrelation was observed between the local cold resistance of peripheral vasomoter during exposure of finger to ice water and the whole cold resistance of autonomic temperature regulation during cold exposure of the whole body. It may be inferred that the subjects with high physical fitness for endurance have low insulative of body fat but have good cold tolerance by enhancement of heat production and preservation of skin temperature.

Effect of regular exercise on cold-induced vasodilation / 体力科学

Eighteen male college students who exercised regularly (the trained group) and 20 students who did not participate in regular exercise activities (the control group) were evaluated.<BR>Cold-induced vasodilation (CIVD) and maximal oxygen intake (VO<SUB>2</SUB>max) for each student were measured in May for four consecutive years. In addition, the motor capacity test devised by the Ministry of Education was given to each student. CIVD and values of motor capacity obtained from the students are summarized as follows;<BR>A. The motor capacity test consists of five items (motor skills) . There was no significant difference in muscle strength between the trained group and the control group. The degrees of improvement in explosive power and endurance capacity over the three years were greater in the trained group. It was significant that the degree of improvement in the total scores for the motor capacity test over the three years was 21% in the trained group in contrast to only 8% in the control group. While VO<SUB>2</SUB>max increased markedly in the trained group, it remained almost unchanged in the control group. The degress of improvement in VO<SUB>2</SUB>max over the three years were 25% in the trained group and 8% in the control group. The values in the control group were almost the same as the physical fitness standards, but those of the trained group were higher than the standards.<BR>B. Mean skin temperature and temperature at first rise in the trained group were higher throughout the three years than those in the control group. The time of temperature rise became shortened over three years in the trained group, but in contrast became rather longer in the control group. The range of variations in the amplitude of temperature was 9°C-13°C in the trained group and around 10°C in the control group. Resistance index (RI) of the trained group was higher in the first year; by the time the students became seniors, there was a 43% increase in RI. In contrast, RI in the control group was almost unchanged. The degree of improvement over the three years was 10% in the latter group.<BR>C. The correlation coefficient of RI with scores from the motor capacity test was 0.499 in the trained group and 0.270 in the control group. The correlation coefficient for all the subjects was 0.605. The correlation coefficient of RI with VO<SUB>2</SUB>max was 0.500 in the trained group, 0.160 in the control group and 0.623 in all the subjects. These values indicate that CIVD values and improvement in motor capacity are closely related, and that the interdependence of these two parameters is particularly strong in trained individuals.<BR>These results indicate that the degree of CIVD is determined not only by genetic factors and chronic exposure to cold temperatures but also by physical training.

A criterion for evaluation of obesity in men based on the relationships between percent body fat and clinical parameters / 体力科学

A study was conducted to derive a criterion for evaluation of obesity based on relationships between percent body fat (%fat) and clinical parameters. The subjects were 457 men aged 18 to 73 years. The results obtained were as follows:<BR>After controlling for the effects of age, maximal oxygen intake per kilogram body weight (VO<SUB>2</SUB>max/wt), alcohol intake and cigarette smoking, %fat showed significant correlations with high-density lipoprotein cholesterol (HDL-C), total cholesterol/HDL-C ratio (TC/HDL-C), fasting blood sugar (FBS), glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), γ-glutamyl transpeptidase (γ-GTP), white blood cell count (WBC), red blood cell count (RBC), systolic blood pressure (SBP), and diastolic blood pressure (DBP) . Values of %fat estimated from borderline values of these clinical parameters ranged from 17.9% to 20.4%.<BR>When the subjects were divided into 11 groups from a below 12% fat group to an above 22% fat group, the 18%, 20%, 21% and above 22% fat groups showed significantly higher occurrence of abnormal values for clinical parameters than the below 12% fat group.<BR>When the subjects were divided into 2 groups, i, e, above (above group) or below (below group) 18%, 19%, 20%, or 21% body fat, the above group always showed a significantly higher occurrence of abnormal values for clinical parameters than the below group.<BR>The subjects were further divided into 3 groups: 250 subjects with %fat below 17.9% (N group), 63 subjects with %fat between 18% and 19.9% (MO group), and 144 subjects with %fat above 20% (O group) . The O group showed the highest occurrence of abnormal values for clinical parameters, followed in order by the MO and N groups. These differences were significant. The O group showed a significantly lower mean value of HDL-C and significantly higher mean values of TC, TC/HDL-C, TG, GPT, SBP, DBP and FBS than the N group. The O group also showed significantly higher mean values for WBC and RBC than the MO and N groups. The O and MO groups showed significantly higer mean values of β-L, γ-GTP and UA than the N group.<BR>From these results and the fact that a value above 20% fat is widely used as a criterion for evaluation of obesity, men with a %fat range of 18.0% to 19.9% are defined as mildly obese, whereas those with above 20% fat are defined as obese.<BR>The subjects were further divided into 3 gooups: %fat below (non-obese) or above (obese) 20%, and VO<SUB>2</SUB>max/wt above (fit) or below (unfit) values recommended by the Ministry of Public Welfare for each age group. One hundred fifty-one subjects were non-obese and fit (NF group), 142 subjects were non-obese and unfit (NU group) and 107 subjects were obese and unfit (OU group) . The NF group showed the lowest occurrence of abnormal values for clinical parameters, followed in order by the NU and OU groups. These differences were significant. Thus, it seems appropriate to evaluate obesity by using a combination of %fat and VO<SUB>2</SUB>max/wt.

A criterion for evaluation of obesity based on the relationship between percent body fat and medical examination parameters / 体力科学

A study was conducted to examine the relationship between percent body fat (%fat) and medical examination parameters. The subjects were 250 women aged 17 to 68 years, who neither drank nor smoked. The results obtained were as follows:<BR>After controlling for the effects of age and maximal oxygen intake per kilogram body weight (VO<SUB>2</SUB>max/wt), %fat showed a significant correlation with high-density lipoprotein cholesterol (HDL-C), total cholesterol/HDL-C ratio (TC/HDL-C), β-lipoprotein (β-L), glutamic oxaloacetic transaminase (GOT), glutamic pyruvic tansaminase (GPT), uric acid (UA), white blood cell count (WBC), red blood cell count (RBC), systolic blood pressure (SBP), and diastolic blood pressure (DBP) . Values of %fat calculated from each regression equation when HDL-C=38mg/dl, TC/HDL-C=4.9, β-L=500 mg/dl, GOT=41mu/ml, GPT=46 mu/ml, UA=5.7mg/dl, WBC=8500/mm3, RBC=520×104/mm3, SBP=159 mmHg, and DBP=94 mmHg were 32.2%, 31.9%, 30.8%, 35.4%, 36.4%, 31.8%, 30.7%, 35.0%, 33.8% and 32.6%, respectively.<BR>The subjects were then divided into 2 groups, above (above group) or below (below group) 30%, 31%, 32%, 33%, 34% or 35% body fat. Wherever the subjects were divided into 2 groups at these values of %fat, the above group showed a significantly higer occurrence of abnormal values for medical parameters than the below group.<BR>The subjects were further divided into 3 groups: 154 subjects with %fat below 29.9% (N group), 47 subjects with %fat between 30% and 34.9% (MO group), and 49 subjects with %fat above 35% (O group) . The O group showed significantly higher occurrence of abnormal values for medical parameters than the MO and N groups. The O group also showed a significantly higher mean value of DBP than the MO and N groups. Furthermore, the O group showed a significantly lower mean value of HDL-C and significantly higher mean values of TC/HDL-C, UA, GOT, GPT, SBP, FBS than the N group. There was no significant difference between the N and MO groups in the occurrence of abnormal values for medical parameters. However, the MO group showed a significantly lower mean value of HDL-C and significantly higher mean values of TC/HDL-C, UA and β-L.<BR>These results suggest that the values of medical parameters become poorer when %fat exceeds 30%, a level widely used in Japan as a criterion for evaluation of obesity.<BR>The subjects were further divided into 3 groups: 50 subjects who were non-obese and fit (NF group) ; 104 subjects who were non-obese and unfit (NU group) ; 88 subjects who were obese and unfit (OU group) . There were significant differences in the occurrence of abnormal values for medical parameters among these groups. The NF group showed the lowest values, followed by the NU and OU groups. Thus, it seems preferable to evaluate individuals using a combination of %fat and VO<SUB>2</SUB>max/wt.