EFFECT OF MUSCLE EXERCISE ON REDUCTION IN MEDICAL EXPENDITURE AMONG ELDERLY / 体力科学

In order to study the effect of muscle exercise on the medical expenditure of the elderly, a three-year exercise program focusing on muscle activity was performed by an intervention group. Individual yearly medical expenditures were collected by 20 participants of the exercise group aver aging 65.2 years of age and 23 control subjects averaging 68.4 years of age with National Health Insurance coverage. Yearly medical expenditures for the exercise group were significantly lower than those of the control group at one and two years after entry. The expenditures increased by 62.6% from 1997 to 1999 in the control group, whereas they increased by only 16.8% for the exer cise group. The results suggest the possibility of the effectiveness of muscle exercise on the reduction in medical expenditure among the elderly.

TEST AND MEASUREMENT FOR MOTOR ABILITY IN ELDERLY PEOPLE / 体力科学

As safety of testing was the highest priority for physical ability measurement in elderly people, their motor ability was evaluated by means of test performance of walking. The purpose of this study was to review existing research on walking tests assessing motor ability of elderly people. Motor ability exerted to perform walking was assumed to be divided into three domains of speed, coordination, and endurance. The maximum and normal speed walking tests were used to measure walking speed in elderly people. The principal determinant of walking speed was stride that was affected by strength of lower limbs. Hurdle walking and the 8-figure walking were used to measure coordination including balance and agility required in walking. Distance walking for 6 and or 12 min was used to measure walking endurance. The 6 min distance walking was the most useful test item to assess the aerobic fitness level of elderly people. The 10 m hurdle walking test and the 6 min distance walking test were selected in Japan Fitness Test for 65-79 years of age.

CAUSAL EFFECT OF STRENGTH TO WALKING ABILITY DEVELOPMENT BY EXERCISE PARTICIPATION OF ELDERLY PEOPLE IN A COMMUNITY / 体力科学

The purpose of this study was to confirm the causal effect model of strength on walking ability development as a result of exercise participation among elderly people in a community, utilizing the latent curve model (LCM) in structural equation modeling (SEM) . Twenty-six male and 57 female subjects, 83 in total, aged 67.8±5.7, 63.9±7.1 and 65.1±6.9 in a pooled sample participated in the exercise program which lasted for two years. Grip strength and sit-ups used in the Japan Fitness Test were measured for muscular strength, 10-m hurdle walk and 6-min walk for walking ability, and the fitness test score for physical ability. The data analysis procedures were as follows : a) analysis of test-retest reliability and construct validity of measurement items, b) analysis of causal structure model of aging, muscular strength and walking ability, c) analysis of variance for repeated measurement of walking performance by sex, age and year, d) analysis of LCM for walking performance development. The highest goodness-of-fit indices of SEM were obtained in the LCM of 10-m hurdle walk performance development (GFI=0.989, AGFI=0.920, CFI=0.998, RMSEA=0.038) . The path coefficient of sit-ups at pre-test effect on the intercept of 10-m hurdle walk performance development was significant (<I>p</I><0.05) . The path coefficients of age to intercept and slope of 10-m hurdle walk development were also significant (<I>p</I><0.05) . It was concluded that walking ability development through participation in exercise age and strength level was more effective for maintaining walking ability in older age.

THE RELATIONSHIP BETWEEN PHYSICAL FITNESS AND INDEX OF COMPETENCE, AND GENERAL HEALTH QUESTIONNAIRE IN THE HOUSEBOUND ELDERLY / 体力科学

The purpose of this study was to examine the relationship between housebound (defined as elderly who go outside less than once a week) and physical fitness test (6 items of grip strength, situps, trunk flexion, foot balance, 10 m hurdle walk, 6 min walk), fitness test score, Tokyo Metropolitan Institute of Gerontology (TMIG) index of competence (3 factors of instrumental self-maintenance, intellectual activity, and social role), and General Health Questionnaire (GHQ) (4 categories of somatic symptoms, anxietynsomnia, social dysfunction, severe depression), considering the differences among gender and age.<BR>The subjects were 296 community-dwelling elderly aged≥65 (mean age ; 75.5±4.9) . Of the subjects, 32% were male, and 57% were elderly aged≥75. Seventy-nine (27.2%) were housebound. The rate of housebound subjects with a full score for intellectual activity, social role on the TMIG sub-scales, 10m-hurdle walk and 6 minute walk was significantly worse than non-housebound subjects. The scores for social dysfunction and severe depression on the GHQ sub-scales for housebound were significantly higher than those for non-housebound ; and few housebound exercised more than 2 times per week or 30 minutes a day. The mental health of male housebound and housebound aged under 75 was the worst among all groups. On the other hand, female housebound and those aged≥75 had lower TMIG and physical fitness results. The characteristics of the housebound were different between genders. Among the housebound aged≥75, grip strength correlated with TMIG and GHQ-28 ; the 10 m hurdle walk correlated with severe depression, instrumental selfmaintenance and intellectual activity ; and the physical fitness score correlated with GHQ-28 after adjusted for age and gender.<BR>Physical fitness correlated with TMIG and GHQ among the housebound; and few housebound exercised in daily life. Improving grip strength and walking ability may reduce the number of housebound.

RELIBILITY AND VALIDITY OF PHYSICAL FITNESS QUESTIONNAIRE WITH SELF-RATING FOR ELDERLY PEOPLE / 体力科学

The purpose of this study was to confirm the reliability and validity of a physical fitness questionnaire (PFQ) with self-rating for elderly people applying structural equation modeling (SEM) . As subjects, 105 community-dwelling older men and women aged 67.1±6.1 years participated in the study to measure 13 PFQ items and 13 performance tests. The data analysis procedures were as follows : a) testing reliability of PFQ ; b) testing of construct validity of PFQ using exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) ; c) testing of criterion-related validity of PFQ to the performance tests using SEM ; d) testing of correlations of the PFQ to walking ability using SEM. Cronbaeh's alpha coefficient for consistency reliability of the PFQ was .83. Four common factors of muscle strength-power, endurance, coordination, and flexibility were extracted in EFA. The high and enough goodness of fit indices were obtained in the confirmatory factor structure model, and in each sub-domain of criterion-related validity to performance tests and correlation to walking ability models. The criterion-related validity coefficient of muscle strength and power was .77, followed by .66 for endurance, .59 for coordination and .82 for flexibility. The correlation coefficient of muscle strength and power to walking ability was -.51, followed by -.58 for coordination, - .43 for endurance and - . 28 for flexibility. These results indicated that the PFQ consisting of 13 items and 4 sub-domains satisfied reliability and construct validity although criterion related validity to performance tests was insufficient. It was concluded that the PFQ is of useful for physical fitness checking of elderly people.

CAUSAL STRUCTURE BETWEEN MUSCLE, MOTOR AND LIVING FUNCTIONS IN COMMUNITY DWELLING ELDERS / 体力科学

The purpose of this study was to confirm the causal structure model of muscle, motor and living functions utilizing structural equation modeling (SEM) . As subjects, 103 community-dwelling older men and women, aged 65.7±6.9years of age, participated in the study to measure muscle cross-sectional area, maximum voluntary contractions, muscle power, 4 physical performance tests, and 16 questionnaires regarding ability of activities of daily living. The causal structure model of muscle, motor and living functions was hypothesized to be a hierarchical causal structure. The causal structure model of muscle function was hypothesized to be a hierarchical causal structure consisting of 3 sub-domains of muscle mass, muscle strength, and muscle power. Data analysis procedures were as follows : a) testing of construct validity of muscle function variables using confirmatory factor analysis (CFA) in SEM ; b) testing of causal structure using SEM ; c) testing of factor invariance using multi-group analysis for gender. The highest goodness of fit indices was obtained in the causal structure model of muscle, motor and living functions (NFI= .928, CFI= .978, RMSEA =.061) . The causal coefficient of muscle function to motor function was .98 (<I>p</I><.05), followed by.34 for motor function to living function. From the results of multi-group analysis, the measurement invariance model indicated the highest goodness of fit indices (TLI=.968, CFI .977) . It was concluded that the hierarchical causal relation was among muscle, motor and living functions, and in which muscle function was consisted of 3 sub-domains.

Relationship Between Reduction of Hip Joint and Thigh Muscle and Walking Ability in Elderly People / 体力科学

The purpose of this study was to investigate the hypothesis that the reduction in walking ability is due to muscle atrophy in the lower limb muscles with aging using equational structure modeling as well as investigate the influence of muscle on walking ability. The subjects consisted of 127 persons (57 males and 70 females) aged 20-84 year, who were grouped into 6 age brackets of 20-39, 40-49, 50-59, 60-69, 70-74, and 75 or older. Using MRI, muscle cross-sectional area was measured on psoas major and thigh muscle (divided into extensor and flexor) . For walking patterns, each subject walked along a 7-m walking passage at normal speed for VTR-recording of the motion. The resulting pictures were used to analyze stride length, trunk inclination and walking speeds. Walking speeds showed a statistically significant decrease in value from the 50's age group in males and the 60's age group in females when compared with the 20-39 age bracket (p<0.05) . In males, a significant co-relationship was observed only between the muscle cross-sectional area of thigh extensor and walking speed (p<0.01) while in females, a significant co-relationship was found between the muscle cross-sectional area of psoas major (p<0.001) /thigh muscle extensor (p<0.01) and walking speed. These results indicate that the muscle atrophy with aging in psoas major and thigh muscle extensor is a factor responsible for the decrease in walking speed. Meanwhile, a difference in sex was observed between the muscle cross-sectional area of psoas major and walking speed. It was considered that the muscle atrophy rate of the female's psoas major being higher than the male's influenced this. Furthermore, it was suggested possibility that the decline of walking ability is due to decreased muscle mass of the lower limbs with aging.

Assessment of Smoking related Risks for Respiratory Symptoms among Elderly People

Disease risk among elderly smokers is considered to be doubled due to their smoking habits and age as compared with elderly non-smokers. The investigators conducted risk assessments of smoking for respiratory symptoms among elderly people.A questionnaire survey on smoking habits and respiratory symptoms was conducted among 3, 000 persons of 56 years of age and over who were randomly selected from suburban residents in a prefecture in Japan in October, 1997. A total 1, 954 or 65.1% of individuals responded, consisting of 42.8% for men and 57.2% for women, with an average age of 73.6 years.In addition to descriptive analysis, multiple logistic regression analysis was conducted. The results are summarized as follows:Smokers accounted for 28.1% of men and 3.6% of women. Among all age-groups, the highest rate of smokers was observed in men of 56-69 years old (34.7%) which was lower than the national average rate for the 60-69 year-old group (56.1% of men and 14.5% of women in ‘97). The odds ratios and 95 percent confidence interval (95%CI) for “having phlegm every day” and “having phlegm for more than 4 days a week” among smokers were 2.06 (95%CI=1.41-3.01) and 2.77(95%CI=1.80-4.27). Significantly higher odds ratios among smokers were also observed for “wheezing” and “shortness of breath when hurrying”.Odds ratios for some respiratory symptoms including “having phlegm for more than 4 days per week” among inhalers were significantly high compared with non-smokers, whereas those among non-inhalers were not significantly different from 1.0.Odds ratios for symptoms of phlegm and wheezing were significantly higher (Odds ratio ≥2.0) among heavy smokers (Brinkman Index [B. I.] >900) compared to non-smokers, while odds ratios of the same symptoms were not different from 1.0 among light smokers (B.I. ≤500).

The simplified evaluation of post-exercise vagal reactivation and application in athletic conditioning / 体力科学

It has been shown that the time constant of heart rate decline for the first 30 sec (T<SUB>30</SUB>) after exercise, at an intensity lower than the ventilatory threshold (VT), can serve as a specific index to assess post-exercise vagal reactivation. The purpose of this study was to validate the use of a simpler alternative index, i. e. %Δ HR<SUB>30</SUB> (the ratio of heart rate decrement for the first 30 sec after exercise) for the evaluation of parasympathetic nervous reactivation, and to examine whether it would be a useful index in the conditioning of athletes. Eighteen college students performed 4 minutes cycle ergometer exercise routines at intensities of 40%, 80%, and 120% VT to compare the %Δ HR<SUB>30</SUB> and the T<SUB>30</SUB>. In addition, the %Δ HR<SUB>30</SUB> was obtained by a field test (4 minutes jogging) in 15 college middle and long distance runners, every morning during summer camp training to assess the state of athletic conditioning. The %Δ HR<SUB>30</SUB> at 80% VT was similar to the value at 40% VT, but significantly different from the value at 120% VT, as was the T<SUB>30</SUB> at 80% VT.<BR>The %Δ HR<SUB>30</SUB> significantly correlated with the T<SUB>30</SUB> and VO<SUB>2</SUB>max. During the camp, the %Δ HR<SUB>30</SUB> was higher on mornings following light training days than on mornings following hard training days. These results suggest that the %Δ HR<SUB>30</SUB>, at an exercise intensity lower than the VT, could be a simple and useful index to evaluate post-exercise parasympathetic nervous reactivation in the conditioning of athletes.

Estimation of cardiorespiratory endurance in young adult men using 12-min submaximal treadmill walk/run test / 体力科学

The purpose of this study was to clarify the validity of 12-min submaximal treadmill walk (TMW) and run (TMR) tests, as indirect measures of cardiorespiratory endurance, and to develop estimation equations of cardiorespiratory endurance using TMW or TMR performance and some other useful items correlating with cardiorespiratory endurance. Fifty-one young adult men, aged 20 -r34 years (22.8±3.6), walked or ran for 12 minutes on the treadmill at the intensity corresponding to the level 13 on the Borg's ratings of perceived exertion (RPE 13), and performed a maximal incremental exercise test. Mean (± SD) of oxygen uptake corresponding to anaerobic threshold (VO<SUB>2</SUB>AT) and maximal oxygen uptake (VO<SUB>2</SUB>max) were 42.0 ± 9.0 ml/kg/min and 55.9 ± 7.4 ml/kg/min, respectively, and mean (± SD) of 12-min walk and run distances were 1221 ± 103 m and 2108 ± 269 m, respectively. Cardiorespiratory endurance indices (VO<SUB>2AT</SUB> and VO<SUB>2</SUB>max) significantly correlated with TMW (r=0.49 and 0.48, respectively) and with TMR (r=0.69 and 0.68, respectively) . A stepwise multiple regression analysis was applied to determine the estimation equations of the cardiorespiratory endurance using VO<SUB>2AT</SUB> or VO<SUB>2</SUB>max as a dependent variable, and TMW or TMR distance, age, resting heart rate (HRrest), and exercise frequency in a week as independent variables. The multiple regression equations of VO<SUB>2AT</SUB> and VO<SUB>2</SUB>max were developed as follows : When TMW distance entered as an independent variable, VO<SUB>2AT</SUB> = 20.781 X<SUB>1</SUB> + 2.298 X<SUB>3</SUB> - 0.29 X<SUB>4</SUB> + 31.855 (r = 0.83, SEE = 5.33 ml/kg/min) : VO<SUB>2</SUB>max =19.941 X<SUB>1</SUB> + 1.127 X<SUB>3</SUB> - 0.208 X<SUB>4</SUB> - 0.656 X<SUB>5</SUB> - 0.853 X<SUB>6</SUB> + 77.884 (r = 0.88, SEE = 3.96 ml/kg/min), and when TMR distance entered as an independent variable, VO<SUB>2</SUB>AT =15.443 X<SUB>2</SUB> + 2.158 X<SUB>3</SUB>- 0.157 X<SUB>4</SUB> + 14.234 (r = 0.90, SEE = 4.18 ml/kg/min) ; VO<SUB>2</SUB>max =10.817 X<SUB>2</SUB> + 1.274 X<SUB>3</SUB> - 0.1946 X4 - 0.504 X<SUB>5</SUB> + 55.234 (r = 0.89, SEE = 3.79 ml/kg/min), where X<SUB>1</SUB> : TMW distance (m), X<SUB>2</SUB>: TMR distance (m), X<SUB>3</SUB> : exercise frequency in a week (d/wk), X<SUB>4</SUB>: HRrest (b/min), X<SUB>5</SUB>: age (yr) and X<SUB>6</SUB>: BMI. It is concluded that cardiorespiratory endurance could be better estimated by a combination of submaximal exercise performance and some easily measurable items correlating with cardiorespiratory endurance such as exercise frequency, circulatory function, chronological age and body composition.

Studies on muscle metabolism and cross-sectional area in the elite Japanese soccer players using NMR / 体力科学

We investigated the muscle energetics using <SUP>31</SUP>P nuclear magnetic resonance (<SUP>31</SUP>P NMR) spectroscopy, muscle cross-sectional area by magnetic resonance imaging (MRI), isokinetic strength, maximal anaerobic power and 40-sec maximal cycling test (40 seconds power) in All Japan soccer players (JPN: n=6), Olympic and Youth representatives (OL: n=6), and Japan Soccer League players (JSL: n=5) . There was no significant difference in muscle energy metabolism measured by <SUP>31</SUP>P NMR between the JPN and the OL or JSL players at rest, during exercise, or in the recovery period. The total muscle cross-sectional area was significantly larger in the JPN players than in the OL players at the upper (70%) and the middle (50%) parts of the thigh (p<0.05) and than in the JSL players in the upper (p<0.01), middle (p< 0.05), and lower (30%) parts (p<0.01) . The isokinetic strength in left leg extension at 180 deg/sec was significantly greater in the JPN players than in the OL players (p<0.05) . Muscle strength was also greater in extension of both legs at 450 deg/sec (left p<0.05, right p<0.01) in the JPN players than in the JSL players. The maximum anaerobic power was significantly greater in the JPN players than in the OL players (p<0.05) and the JSL players (p<0.05), and the anaerobic power per kilogram of body weight was significantly higher in the JPN players than in the JSL players (p<0.01) . There was no significant difference in the 40 seconds power among the three groups. These results suggest that the JPN players have greater muscle power than the OL or JSL players because of the differences in the muscle mass.