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Biomedical subjects

C J Caspersen

Publications and source records attributed to C J Caspersen.

At least 37 records · Page 2Linked to original sources
PubMed1993

A survey for assessing physical activity among older adults.

In 1988, the Yale Physical Activity Survey (YPAS) was designed and then administered to healthy older populations of volunteers (aged 60-86) to establish its 2-wk repeatability and relative validity. Among the 76 volunteers in the repeatability substudy, correlation coefficients between the two administrations of the survey for the eight YPAS summary indices ranged from 0.42 (P = 0.0002) to 0.65 (P = 0.0001). Among the 25 subjects in the validation substudy, weekly energy expenditure (r = -0.47; P = 0.01) and daily hours spent sitting (r = 0.53; P = 0.01) correlated with resting diastolic blood pressure, while the YPAS activity dimensions summary index (composed of questions on vigorous activity, leisurely walking, moving, sitting, and standing) correlated positively with estimated VO2max (r = 0.58; P = 0.004) and inversely with percent body fat (r = -0.43; P = 0.03). The YPAS index of vigorous activity also correlated positively with estimated VO2max (r = 0.60; P = 0.003) and the moving index correlated marginally with body mass index (r = -0.37; P = 0.06). We conclude that the YPAS demonstrates adequate repeatability, and some validity by correlating with several physiologic variables reflecting habitual physical activity. The value of the YPAS, however, in accurately assessing low intensity activity remains to be established.

Activities of Daily Living↗
PubMed1992

Abatement of exertional perceptions following dynamic exercise: physiological mediators.

Perceptual and physiological congruity was examined during recovery from high-intensity dynamic exercise. Nine males (24.8 +/- 0.6 yr; VO2max; 52.3 +/- 1.5 ml.kg-1.min-1) undertook in random order four maximal treadmill protocols. Treadmill speed was held constant (5.3 km.h-1) while grade was incremented by 2, 4, 6, or 8% every 3 min for protocols A, B, C, and D, respectively. Ratings of perceived exertion (RPErec; Borg 15-point scale), ventilation (VE), respiratory rate (RR), oxygen uptake (VO2), and heart rate (HR) were measured preexercise and during each min of a 12-min supine postexercise period that immediately followed treadmill testing. Ratings were obtained for the peripheral perceptual signal arising from the legs (RPErec-L), the respiratory-metabolic signal from the chest (RPErec-C), and the overall body signal (RPErec-O). Blood pH was measured preexercise and during min 1, 6, and 12 of recovery. RPErec-L and RPErec-O were lower (P less than 0.05) and blood pH higher (p less than 0.05) following protocol A than D at all recovery time points. RPErec-C, VE, and RR were lower (P less than 0.05) for protocol A than D at all recovery time points. Differences among protocols were not noted for VO2 or HR at any recovery time point. The decay in signal strength for both RPErec-L and RPErec-O following high-intensity exercise reflected the abatement of metabolic acidosis. RPErec-O was influenced by the abatement of pulmonary ventilation during the postexercise period.

Acidosis↗
PubMed1991

The prevalence of selected physical activities and their relation with coronary heart disease risk factors in elderly men: the Zutphen Study, 1985.

Physical activity patterns and their relation with coronary heart disease risk factors are described for a representative sample of 863 Dutch men, 65-84 years old, who participated in the 1985 survey of the Zutphen cohort of the Seven Countries Study. Cross-sectional results revealed a median total of reported physical activity of about 1 hour and 20 minutes per day; only 5.8% reported no physical activity. The percentage of participation and total weekly time spent in physical activity decreased as age increased; the decrease was less pronounced for walking, bicycling, gardening, and doing odd jobs than for sports, hobbies, and work. Statistically significant mean differences were found among quartiles of total weekly physical activity for both total cholesterol and high-density lipoprotein cholesterol (HDL cholesterol); however, only the differences for HDL cholesterol remained significant (p = 0.045) after adjusting for potential confounders. Statistically significant regression coefficients (p less than 0.05) were found for the independent association between walking and total cholesterol and between gardening and total cholesterol, HDL cholesterol, and systolic blood pressure, after adjusting for confounders. Total weekly physical activity and specific activities, e.g., gardening and walking, demonstrated generally favorable associations with cholesterol and systolic blood pressure.

Aged↗
PubMed1990

Test characteristics of self-reported hypertension among the Hispanic population: findings from the Hispanic Health and Nutrition Examination Survey.

Data from the Hispanic Health and Nutrition Examination Survey conducted from 1982 to 1984 were analyzed for the sensitivity, specificity, and positive and negative predictive value of self-reported hypertension in 5195 Hispanics of both sexes between the ages of 18 and 74 years. On the basis of a hypertension definition of 140/90 mmHg or of the use of antihypertensive medications, overall sensitivity of self-reported hypertension was 56% for Mexican-Americans, 71% for Cuban-Americans and 72% for Puerto Ricans. Sensitivity was higher among women, among the obese, and among those with access to a regular place for medical care; increased with increasing age; and decreased with education and the time interval since last medical visit. Independent associations for sensitivity were noted for sex, body mass index (BMI), and time interval since last medical visit among Mexican-Americans; and for time interval since last medical visit and for being divorced or separated for Cuban-Americans. Overall positive predictive value reached 49% among Mexican-Americans, 53% among Cuban-Americans, and 39% among Puerto Ricans. Raising the hypertension-threshold to 160/95 mmHg tended to increase the sensitivity but reduced the positive predictive value.

Adolescent↗
PubMed1989

Identifying correlates of walking for exercise: an epidemiologic prerequisite for physical activity promotion.

This study was designed to identify correlates of walking for exercise in adults. Over 2,050 (43.4% response rate) responses to a mailed questionnaire were analyzed. Possible correlates of walking were based on learning theory and previous empirical observations. Respondents averaged less than 1 hr of walking for exercise per week. Women and older adults (greater than or equal to 50 years) reported significantly (P less than 0.05) greater walking than men or younger respondents. Multiple regression analyses were conducted for selected subgroups of respondents. Analyses were conducted on subjects who reported no regular vigorous exercise. Multiple correlation coefficients ranged from 0.32 to 0.48, and most reached significance (P less than 0.05). For the most sedentary subgroups, self-efficacy, family and friend support, and consumption of a heart-healthy diet were repeatedly associated with walking for exercise. It was concluded that an economically secure and well-educated Caucasian sample performs an inadequate amount of walking to ensure benefits such as prevention of cardiovascular disease. Longitudinal analyses are required to confirm the influence of social learning variables. Tentatively, interventions that increase family and friends' support for walking and that enhance perceived self-efficacy should be developed.

Adult↗
PubMed1989

A multivariate study of determinants of vigorous exercise in a community sample.

The purpose of this study was to explore the associations between several social learning theory variables and self-reported vigorous exercise and to consider the implications for exercise promotion. A random sample of adults in San Diego, California, was surveyed by mail. The 2,053 respondents (response rate, 43.4%) overrepresented Caucasian, affluent, and well-educated groups. A model of 24 variables accounted for 0.27 of the variance in exercise, and results strongly supported social learning theory. The strongest correlates were self-efficacy (i.e., confidence in the ability to exercise in specific situations), perceived barriers to exercise, modeling, dietary habits, support from friends, and age. Smoking was inversely associated with exercise in men only. We encourage researchers to conduct intervention trials to test the hypotheses generated in this study.

Adult↗
PubMed1989

Physical activity epidemiology: concepts, methods, and applications to exercise science.

This review was conducted to provide the reader with a brief overview of the science of epidemiology as applied specifically to physical activity as a behavior. Definitions were offered for epidemiology, for physical activity, and finally for physical activity epidemiology. In addition to considering epidemiologic concepts, this review stressed the importance of carefully measuring physical activity--perhaps the principal function of anyone who ultimately claims to be a physical activity epidemiologist. The breadth and scope of physical activity epidemiology are extensive and there is fertile ground for continuing to apply physical activity epidemiology to exercise science well into the future. This chapter should provide the exercise scientist with a firm foundation to begin his or her trek into the realm of physical activity epidemiology.

Epidemiologic Methods↗
PubMed1988

Effect of simulated altitude erythrocythemia in women on hemoglobin flow rate during exercise.

The effect of simulated altitude erythrocythemia on hemoglobin flow rate and maximal O2 uptake (VO2max) was determined for nine women sea-level residents. Test conditions included normoxia and normobaric hypoxia (16% O2-84% N2). Cycle tests were performed under normoxia (T1-N) and hypoxia (T1-H) at prereinfusion control and under hypoxia 48 h after a placebo infusion (T2-H) and 48 h after autologous infusion of 334 ml of erythrocytes (T3-H). Hematocrit (38.1-44.9%) and hemoglobin concentration (12.7-14.7 g.dl-1) increased from control to postreinfusion. At peak exercise, VO2max decreased from T1-N (2.40 l.min-1) to T1-H (2.15 l.min-1) then increased at T3-H (2.37 l.min-1). Maximal arterial-mixed venous O2 difference decreased from T1-N to T1-H and increased at T3-H. Cardiac output (Q), stroke volume, heart rate, and total peripheral resistance during maximal exercise were unchanged from T1-N through T3-H. Hemoglobin flow rate (Hb flow) at maximum did not change from T1-N to T1-H but increased at T3-H. When compared with submaximal values for T1-N, VO2 was unchanged at T1-H and T3-H; Q increased at T1-H and decreased at T3-H; arterial-mixed venous O2 difference decreased at T1-H and increased at T3-H; Hb flow did not change at T1-N but increased at T3-H. For young women, simulated altitude erythrocythemia increased peak Hb flow and decreased physiological altitude (227.8 m) but did not affect maximum cardiac output (Qmax).

Adult↗
PubMed1988

A cost-effectiveness analysis of exercise as a health promotion activity.

We used cost-effectiveness analysis to estimate the health and economic implications of exercise in preventing coronary heart disease (CHD). We assumed that nonexercisers have a relative risk of 2.0 for a CHD event. Two hypothetical cohorts (one with exercise and the other without exercise) of 1,000 35-year-old men were followed for 30 years to observe differences in the number of CHD events, life expectancy, and quality-adjusted life expectancy. We used jogging as an example to calculate cost, injury rates, adherence, and the value of time spent. Both direct and indirect costs associated with exercise, injury, and treating CHD were considered. We estimate that exercising regularly results in 78.1 fewer CHD events and 1,138.3 Quality Adjusted Life Years (QALYs) gained over the 30-year study period. Under our base case assumptions, which include indirect costs such as time spent in exercise, exercise does not produce economic savings. However, the cost per QALY gained of $11,313 is favorable when compared with other preventive or therapeutic interventions for CHD. The value of time spent is a crucial factor, influencing whether exercise is a cost-saving activity. In an alternative model, where all members of the cohort exercise for one year, and then only those who like it or are neutral continue, exercise produces net economic savings as well as reducing morbidity.

Adult↗
PubMed1987

Physical activity and the incidence of coronary heart disease.

Our review focuses on all articles in the English language that provide sufficient data to calculate a relative risk or odds ratio for CHD at different levels of physical activity. The inverse association between physical activity and incidence of CHD is consistently observed, especially in the better designed studies; this association is appropriately sequenced, biologically graded, plausible, and coherent with existing knowledge. Therefore, the observations reported in the literature support the inference that physical activity is inversely and causally related to the incidence of CHD. The two most important observations in this review are, first, better studies have been more likely than poorer studies to report an inverse association between physical activity and the incidence of CHD and, second, the relative risk of inactivity appears to be similar in magnitude to that of hypertension, hypercholesterolemia, and smoking. These observations suggest that in CHD prevention programs, regular physical activity should be promoted as vigorously as blood pressure control, dietary modification to lower serum cholesterol, and smoking cessation. Given the large proportion of sedentary persons in the United States (91), the incidence of CHD attributable to insufficient physical activity is likely to be surprisingly large. Therefore, public policy that encourages regular physical activity should be pursued.

Adult↗
PubMed1986

Test-retest reliability of the Minnesota Leisure Time Physical Activity Questionnaire.

The test-retest reliability of the Minnesota Leisure Time Physical Activity Questionnaire was assessed by two administrations of the questionnaire at a five-week interval in 140 adults from a general population sample and at a two-week interval in 150 male participants in the Multiple Risk Factor Intervention Trial (MRFIT). In both study populations, there was a slight, nonsignificant drop in reported leisure time energy expenditure between the test and the retest. The largest test-retest differences in estimated energy expenditure were found among those reporting greater levels of energy expenditure. Nevertheless, in both study populations Spearman rank correlation coefficients between the test and retest were high--0.79 to 0.88 for total activity and ranging 0.69-0.86 among the light, moderate, and heavy intensity subcategories. The high reliability of the Minnesota Leisure Time Physical Activity Questionnaire corroborates its utility in epidemiologic research.

Adult↗
PubMed1985

Leisure time physical activity and its relationship to coronary risk factors in a population-based sample. The Minnesota Heart Survey.

Energy expenditure in leisure time physical activity was measured using the Minnesota Leisure Time Physical Activity Questionnaire in a probability sample of 25- to 74-year-old residents of the seven-county metropolitan area of Minneapolis-St. Paul, Minnesota. Geometric mean estimates of leisure time physical energy expenditure were 193 kcal per day for men and 111 kcal per day for women. Only 34% of men and 17% of women expended 2,000 kcal or more per week in leisure time physical activity. Energy expenditure, especially in heavy intensity activities, declined with age, more so for women than men. Significant associations were observed between leisure time physical activity, particularly heavy intensity activity, and other coronary heart disease risk factors. Greater heavy intensity activity was associated with higher education (r = 0.14 to 0.26), greater Type A behavior (r = 0.14 to 0.15), higher serum high density lipoprotein (HDL) cholesterol levels (r = 0.09 to 0.10), lower serum thiocyanate (r = 0.10 to -0.14), lower body mass index (r = -0.10 to -0.11), lower heart rate (r = -0.07 to -0.10), and lower systolic blood pressure (r = -0.06 to -0.09). Thus, although energy expenditure was generally low in this population, greater leisure time physical activity for the most part was associated with lower coronary risk factors.

Adult↗
PubMed1984

Exercise in the management and rehabilitation of selected chronic diseases.

The effects of exercise on the progression of eight chronic diseases or medical conditions are reviewed. In the case of coronary artery disease (CAD), there is some suggestive evidence that exercise is associated with a survival advantage. Exercise does not consistently increase blood flow in peripheral vascular disease, nor does it improve lung function in patients with chronic obstructive pulmonary disease. However, it is associated with increased physical work capacity in these two conditions. Preliminary studies suggest that exercise may be beneficial in the management of pulmonary secretions in patients with cystic fibrosis. Exercise has no therapeutic role in acute exacerbations of rheumatoid arthritis, but in the chronic stages, exercise that does not cause pain may be beneficial. Exercise is the focal point of chronic pain syndrome programs. With exercise programs, patients with chronic pain can increase physical work capacity with a decrease in complaints of pain. Patients with osteoporosis appear to benefit from a carefully programmed low-level exercise program that avoids back flexion exercises. Blood glucose, hypertension, and serum lipid levels improve with exercise in patients with dialysis-dependent renal failure.

Adolescent↗
PubMed1984

Hemoglobin concentration and aerobic work capacity in women following induced erythrocythemia.

The effect of induced erythrocythemia on hemoglobin concentration ([Hb]) and aerobic work capacity was determined for nine women. Cycle tests were performed at prereinfusion (T1), 2 days after a placebo infusion (T2), 2 days postreinfusion of 334 ml of red blood cells (T3), 8 days postreinfusion (T4), and 14 days postreinfusion (T5). T1 and T2 responses did not differ, negating a placebo effect. [Hb] increased from 12.7 g X dl at T1 to 14.7 g X dl at T3 and then remained constant at T4 and T5. Hematocrit increased from 38.1% at T1 to 44.9% at T3 and then remained constant at T4 and T5. Submaximal O2 uptake (VO2) and stroke volume (SV) did not change from T1 through T5. Submaximal cardiac output (Q) and heart rate (HR) decreased from T1 to T3 and then remained constant at T4 and T5. Arteriovenous O2 difference increased from T1 to T3 and then remained constant at T4 and T5. Maximal VO2 was greater at T3 (2.65 l X min-1), T4 (2.66 l X min-1), and T5 (2.60 l X min-1) than at T1 (2.41 l X min-1). Physical work capacity was greater at T3 (10,740 kg X m), T4 (10,980 kg X m), and T5 (10,380 kg X m) than at T1 (8,747 kg X m). Maximal values for Q, HR, and SV were unchanged from T1 through T5. At maximum, arteriovenous O2 difference and Hb flow rate increased from T1 to T3 and then remained constant at T4 and T5. The greater postreinfusion [Hb] improved O2 transport capacity and appeared to regulate circulatory responses.

Adult↗