Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Physics”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3Linked to original sources
PubMed1998

Associations between skeletal muscle properties, physical fitness, physical activity and coronary heart disease risk factors in men.

High physical fitness and physical activity are associated with favourable lipid levels, especially a high level of high density lipoprotein cholesterol (HDL-C). A person's skeletal muscle properties, metabolism and percentage of different muscle fibres (ST-%), which may modify coronary heart disease (CHD) risk factors, such as serum insulin, obesity and serum sex hormones may also influence his fitness level and leisure-time physical activity. We studied the associations of physical fitness, physical activity and ST-% with serum lipids and lipoproteins in 72 healthy men. Their parameters were compared with those of 20 men with defined CHD. Significant interrelationships between ST-%, fitness and leisure-time physical activity index (LTPAI) were observed. Multiple regression analysis showed that ST-%, fitness and leisure-time physical activity explained about 32% of the variation in HDL-C in the healthy men. In healthy men ST-% correlated positively with fitness (r(s) = 0.62, P < 0.001) and with LTPAI (r(s) = 0.62, P < 0.001). Fitness level also correlated significantly with LTPAI (r(s) = 0.81, P < 0.001). Serum insulin showed negative associations with ST-% (r(s) = -0.63, P < 0.001) and fitness (r(s) = -0.54, P < 0.001) and LTPAI (r(s) = -0.62, P < 0.001). Free fraction of testosterone correlated negatively with serum HDL-C level (r(s) = -0.34, P < 0.01), with fitness (r(s) = -0.41, P < 0.001) and with LTPAI (r(s) = -0.54, P < 0.001). In sedentary men with the lowest fitness and physical activity the mean of ST-% (45%) was similar to that in CHD patients (44%). However, ST-% in men in the highest tertile of physical activity and fitness (68%) was significantly higher than in CHD patients and in men in the lowest tertile of physical activity and fitness. Skeletal muscle enzyme activity in lipid metabolism was significantly lower in both CHD patients and in sedentary and low-fit men than that in fitter and physically active men. The present data imply that skeletal muscle properties are important determinants of risk profiles, such as physical activity, fitness and serum lipid and lipoprotein patterns. Although fitness is a graded, independent predictor of mortality from CHD, a relatively high fitness level is not enough. This was clearly observed in the clustering analysis, in which the healthy men, according to their ST-%, fitness, leisure-time physical activity and serum sex hormone binding globulin (SHBG), fell into three natural groups: (i) Inactive men with lowest ST-% (mean 42%), lowest fitness (10.7 METs) and lowest HDL-C (1.36 mm/l); (ii) Fit men with high ST-% (66%), high fitness (14.5 METs) and moderately high HDL-C (1.54 mol/l); (iii) Active men with high ST-% (66%), highest fitness (14.9 METs) and highest serum HDL (1.83 mmol/l). The results support the idea that both fitness and physical activity give further protection against CHD by modifying risk factors. Our findings also suggest that skeletal muscle properties should be considered in the studies which assess CHD risk factors and their modifications especially in the field of health-related fitness.

Adult↗
PubMed1992

[Development of a method for estimation of physical fitness age for the evaluation of physical performance levels].

The aims of this study are to develop a method for estimation of physical fitness age for the evaluation of physical performance levels and to examine the efficacy and adaptability of the method. Physical fitness data collected on 15,845 subjects from 23 health promotion centers in Japan, during a 2-year period, 1985-1986, were analysed by correlation analysis to find factors which affect physical performance. From this analysis, stature and exercise habit were selected as factors to be considered in the computation of physical fitness age. For determination of physical fitness and its relation to chronological age, four tests, side step, sit-ups, vertical jump and wing lift were selected from results of correlation and multiple regression analysis and an estimation equation for physical fitness age was developed by stepwise multiple regression analysis, in which the subjective variable is physical fitness data and objective variables are chronological age and height, on 9,528 people without habitual physical activities. Physical fitness age for each fitness test was calculated from the equation and mean individual physical fitness age computed. The suitability of the developed method was tested on other groups with results showing that the developed method was generally applicable to the other group and was exact enough to evaluate the characteristics of the physical level of the group. Analysis of the relation between health indices and physical fitness age obtained by this new method, revealed that the group in which physical fitness age is inferior to chronological age contained relatively more hypertensive patients and obese people.

Adult↗
PubMed1983

Physical fitness of physical therapy students.

Physical fitness norms do not exist for physical therapists or physical therapy students. This lack, in part, reflects the complexity of physical fitness and the scarcity of data reported on physical fitness norms of other populations. This report describes the methods used and the results obtained for 16 physical fitness factors of 98 female and 13 male physical therapy upperclassmen and discusses the implications of physical fitness in the practice of physical therapy. Means, standard deviations, ranges, and percentile rankings are given by sex for each of the 16 fitness factors. The purpose of this study was to begin to establish physical fitness norms. As physical fitness norms are established, it will be possible to determine how norms of physical therapists and physical therapy students compare with established values.

Adult↗
PubMed2005

Prospective study of physical activity and physical function in early old age.

BACKGROUND: In the elderly, higher levels of physical function have consistently been associated with higher levels of physical activity. In this study, we test the hypothesis that physical activity earlier in the life course preserves high physical function over an extended period of time, before the onset of major age-related declines in physical function. METHODS: A cohort study with an average of 8.8 years of follow-up (1991-1993 to 2001). Logistic regression analyses were conducted adjusting for long-standing illness, baseline physical function, smoking, body mass index, and employment grade. Participants were 6398 London-based civil servants aged 39 to 63 years at baseline, 90% of whom were working. The main outcome measure was physical function measured by the Short Form (SF-36) General Health Survey. RESULTS: Relatively fit and healthy, mainly working, middle-aged men and women who were physically active at recommended levels, were more likely to report high physical function at follow-up, compared to their sedentary counterparts (odds ratio 1.63, 95% confidence interval 1.32-2.00). The association between initial level of physical activity and high physical function at follow-up remained after adjustment for baseline level of physical function and the presence of long-standing illness. CONCLUSIONS: Participation in a physically active lifestyle during mid-life appears to be critical to the maintenance of high physical function in those who are fit and well enough to work and do or do not report any long-standing illness.

Adult↗
PubMed2006

Individual, social environmental, and physical environmental influences on physical activity among black and white adults: a structural equation analysis.

BACKGROUND: Social ecological models suggest that conditions in the social and physical environment, in addition to individual factors, play important roles in health behavior change. Using structural equation modeling, this study tested a theoretically and empirically based explanatory model of physical activity to examine theorized direct and indirect effects of individual (e.g., motivation and self-efficacy), social environmental (e.g., social support), and physical environmental factors (e.g., neighborhood quality and availability of facilities). METHOD: A community-based sample of adults (N = 910) was recruited from 2 public health centers (67% female, 43% African American, 43% < $20,000/year, M age = 33 years) and completed a self-administered survey assessing their current physical activity level, intrinsic and extrinsic motivation for physical activity, perceived social support, self-efficacy, and perceptions of the physical environment. RESULTS: Results indicated that (a) perceptions of the physical environment had direct effects on physical activity, (b) both the social and physical environments had indirect effects on physical activity through motivation and self-efficacy, and (c) social support influenced physical activity indirectly through intrinsic and extrinsic motivation. For all forms of activity, self-efficacy was the strongest direct correlate of physical activity, and evidence of a positive dose-response relation emerged between self-efficacy and intensity of physical activity. CONCLUSIONS: Findings from this research highlight the interactive role of individual and environmental influences on physical activity.

Adolescent↗
PubMed2005

Relations of perceived physical self-efficacy and motivational responses toward physical activity by urban high school students.

To be effective in promoting physical activity among urban, minority adolescents, the factors and psychological processes that motivate them to engage in and maintain a physically active lifestyle should be examined. The relation of physical self-efficacy and motivational responses toward physical activity in 46 urban minority adolescents was explored. As hypothesized, there were significant positive relationships among Percieved Physical Ability, Physical Self-presentation Confidence, Effort, and Enjoyment (coefficients ranged from .29 to .80), suggesting that participants who had higher perceived physical ability were likely to report higher perceptions of self-presentation, more enjoyment of physical activity, and harder work in physical activity. These results indicate specific relationships among Effort, Enjoyment, Perceived Physical Ability, and Physical Self-presentation Confidence in this sample. Physical self-efficacy appears to be a stronger predictor of motivational responses in physical activity. Practical implications for physical educators include incorporating strategies known to develop self-efficacy, such as mastery experiences involving successive trials of increasing difficulty, self-observation, external feedback, peer modeling, and verbal persuasion.

Adolescent↗
PubMed1996

Amount and intensity of physical activity, physical fitness, and serum lipids in men. The MARATHOM Investigators.

Physical activity improves one's lipid profile and increases physical fitness. The present study was aimed at determining the association of amount and intensity of leisure time physical activity with serum lipid profile and physical fitness. A total of 537 healthy men aged 20-60 years were recruited in a quota sampling frame for measurement of physical activity energy expenditure at two different levels. The Minnesota Leisure Time Physical Activity Questionnaire was administered. Serum lipid and lipoprotein levels were measured, and all participants were given an exercise test. Physical activities with an intensity greater than 7 kcal/minute were significantly associated (p < 0.01) with a higher level of high density lipoprotein (HDL) cholesterol and a lower atherogenic index (total cholesterol:HDL cholesterol). Independently of other confounding variables, each average 100 kcal/day expended in leisure time physical activity with an intensity greater than 7 kcal/minute during the previous year was associated with an increase of 2.09 mg/dl (0.054 mmol/liter) in HDL cholesterol and a decrease of 0.23 in atherogenic index. However, only physical activity with an intensity greater than 9 kcal/minute was associated with decreases in total cholesterol, non-HDL cholesterol, and log(triglycerides). Better physical fitness was associated with physical activities of intensities above 5 kcal/minute. There is a threshold in the intensity of exercise associated with serum lipid profile (7 kcal/minute) and physical fitness (5 kcal/minute). Above the former threshold, the relation between amount of physical activity and lipid levels is linear for total cholesterol, HDL cholesterol, non-HDL cholesterol, and atherogenic index and is logarithmic for triglycerides.

Adult↗
PubMed1995

Associations of physical activity with performance-based and self-reported physical functioning in older men: the Honolulu Heart Program.

OBJECTIVE: To examine the association of self-reported physical activity with performance-based and self-reported physical functioning measured 3 to 5 years later. DESIGN: A population-based, longitudinal study. SETTING: The island of Oahu, Hawaii. PARTICIPANTS: Subjects were 3640 Japanese-American men older than 70 years of age. MEASUREMENTS: Estimated daily energy expenditure evaluated from self-reported engagement in a variety of activities determined from a mail survey in 1988; physical functioning status determined from both self-report and performance-based measures 3 to 5 years later. The effect of physical activity on physical functioning scores was determined through multiple logistic regression and analysis of covariance techniques for subjects who had chronic diseases as well as those in a healthy subsample. RESULTS: For the healthy subsample, those who were highly active in 1988 were more likely to have optimal function for the basic activities of daily living score (odds ratio 2.3; confidence interval (CI) 1.1 to 4.9), home management skills score (odds ratio 1.5; CI 1.1 to 2.1), and physical endurance-type tasks score (odds ratio 1.7; CI 1.2 to 2.4) than subjects classified as low active. A significant linear trend was found additionally across physical activity level for time to walk 10 feet and grip strength (P values < .001). Similar results were found for subjects with chronic diseases; however, most of the benefit of physical activity for this subsample occurred for subjects who were at least physically active at a moderate level. CONCLUSION: Engaging in physical activity is predictive of a high level of physical functioning in older men with and without chronic diseases. Participation in at least moderate physical activity may be sufficient to maintain optimal physical functioning in subjects afflicted with chronic diseases.

Activities of Daily Living↗
PubMed2004

Public health and clinical recommendations for physical activity and physical fitness: special focus on overweight youth.

Numerous physical activity and physical fitness recommendations exist for youth. To date, however, no investigator has systematically reviewed these public health and clinical guidelines to determine whether the recommendations address overweight youth. This review examines youth-oriented physical activity and physical fitness recommendations for both the public health community and the clinical community, and assesses how overweight youth are specifically targeted by each of these two groups. Our review determined the extent to which the recommendations assessed four components of physical activity (i.e. frequency, intensity, duration and type) and four components of physical fitness (i.e. cardiorespiratory capacity, strength, flexibility and body composition). We further reviewed clinical recommendations to determine how they included two facets of the physician-patient encounter: assessment and counselling. After identifying all current physical activity and physical fitness recommendations for youth, we evaluated whether public health (n = 13) and clinical recommendations (n = 12) addressed physical activity and physical fitness for overweight youth. Findings revealed inconsistent, yet explicit, recommendations for the public health community where most organisations (12 of 13, 92%) included > or =3 physical activity components. In addition, organisations encouraged volumes of daily moderate- to vigorous-intensity physical activity for youth ranging from 30-60 or more minutes. Recommendations for the clinical community generally did not provide explicit physical activity and fitness recommendations to advise physicians on the assessment and counselling of patients and their families. Overweight youth were addressed within some recommendations (6 of 12, 50%) for the clinical community, but within few recommendations (2 of 13, 15%) for the public health community. To best inform public health and clinical communities, organisations developing future recommendations should include information fully documenting the decision-making processes used to develop the recommendations. In cases where mutual goals exist, public health and clinical communities should consider collaborating across agencies to develop joint recommendations.

Adolescent↗
PubMed1995

Physical activity, physical fitness, and coronary heart disease risk factors.

The relationships between physical activity, physical fitness, and coronary heart disease risk factors measured in a large community sample were evaluated. Self-reported physical activity using a single question, maximal oxygen consumption estimates derived from the Pawtucket Heart Health Step Test, blood pressure, nonfasting lipids, and body mass index were cross-sectionally evaluated in 381 men and 556 women. The correlation of estimated maximal oxygen consumption and self-reported physical activity was modest but statistically significant (r = 0.13 in men and r = 0.19 in women). Blood pressure, body mass index, and HDL cholesterol were correlated with physical fitness (r = 0.24-0.65) and correlated to self-reported physical activity (r = 0.09-0.14). Evaluation of coronary heart disease risk factors using both physical activity and physical fitness revealed a complex relationship that generally showed a stronger relationship with measures of physical fitness than with physical activity. This study suggests that simultaneous measurement of physical activity and physical fitness may be useful in epidemiologic studies of habitual physical activity and chronic disease.

Adolescent↗
PubMed2000

Daily physical activity and physical fitness from adolescence to adulthood: A longitudinal study.

The stability of physical fitness and physical activity in Flemish males from 18 to 40 years of age was investigated. In addition, effects of a consistently low-activity or high-activity level during the same age period on physical fitness were studied. The sample consisted of males who were followed longitudinally from age 13 to age 18 years, and were remeasured at the ages of 30, 35, and 40 years. Complete data about physical fitness and physical activity between 13 and 40 years were available for 130 subjects. Stability was measured using Pearson autocorrelations and simplex models. Multivariate analysis of variance (MANOVA) for repeated measurements was used to look for the effects of activity level on physical fitness. Simplex models showed higher stability coefficients than Pearson correlations, and stability of physical fitness was higher than stability of physical activity. Physical fitness showed the highest stability in flexibility (r = 0.91 between 18 and 30 years, r = 0.96 for both the 30-35 and 35-40 ages intervals), while physical activity showed the highest stability during work (r between 0.70 and 0.98 for the 5-year intervals). Results from MANOVA indicated that for some fitness characteristics the high-active subjects were more fit than their low-active peers. Stability of physical activity was higher than assumed and, therefore, it is a useful and independent indicator for further research. Although possible confounding factors are present (e.g., heredity), a higher level of physical activity during work and leisure time on a regular basis benefits physical fitness considerably. Am. J. Hum. Biol. 12:487-497, 2000. Copyright 2000 Wiley-Liss, Inc.

Journal Article↗
PubMed2006

Physical and psychological functioning of daily living in relation to physical activity. A longitudinal study among former elite male athletes and controls.

BACKGROUND AND AIMS: Physical exercise plays an important role in the prevention and reduction of disabilities in elderly people. The aim of this study was to determine the role of physical activity in the physical and psychological functioning of daily living in a cohort of former elite male athletes representing different sports, and controls of middle and old age. METHODS: Subjects were 664 former elite male athletes (mean age 64.4 years) and 500 controls (62.0 years) in middle and old age. Subjects were mailed "Physical activity and health survey" questionnaires in 1985 and 1995. The primary outcomes the physical and psychological functioning of daily living--were assessed in 1995 using items from the Mini-Finland Health Survey. Logistic regression was used for longitudinal as well as cross-sectional analyses to estimate odds ratios (OR) for poor physical and psychological functioning of daily living in relation to recreational physical activity adjusted for age, sport group, life-style, BMI, mood, chronic diseases, personality characteristics, life-events and socio-economic status. RESULTS: In the longitudinal analysis, low levels of physical activity (lowest MET quintile vs highest quintile) in 1985 (OR 4.91, 95% confidence interval (CI) 2.02-11.9), older age (> or =70 yrs vs under 60 yrs OR 9.93, 95% CI 4.90-20.2), depression (OR 2.03, 95% CI 1.01-4.09) and anxiety in 1995 (OR 2.67, 95% CI 1.34-5.32) increased the risk of poor physical functioning of daily living in 1995, whereas an increase in a physical activity between 1985-1995 (OR 0.89, 95% CI 0.83-0.95) protected against poor physical functioning of daily living. A history of participating in specific types of sports, especially among certain power sports (weight-lifting and track & field throwers) (OR 0.19, 95% CI 0.06-0.60) and team sports (OR 0.34, 95% CI 0.15-0.81) did reveal a significant protective effect against poor psychological functioning of daily living in the longitudinal analysis. CONCLUSIONS: This study suggests that an increase in physical exercise supports physical daily functionality. A specific history of sports participation promotes psychological well-being at an older age.

Activities of Daily Living↗
PubMed2005

Exercise and well-being: a review of mental and physical health benefits associated with physical activity.

PURPOSE OF REVIEW: This review highlights recent work evaluating the relationship between exercise, physical activity and physical and mental health. Both cross-sectional and longitudinal studies, as well as randomized clinical trials, are included. Special attention is given to physical conditions, including obesity, cancer, cardiovascular disease and sexual dysfunction. Furthermore, studies relating physical activity to depression and other mood states are reviewed. The studies include diverse ethnic populations, including men and women, as well as several age groups (e.g. adolescents, middle-aged and older adults). RECENT FINDINGS: Results of the studies continue to support a growing literature suggesting that exercise, physical activity and physical-activity interventions have beneficial effects across several physical and mental-health outcomes. Generally, participants engaging in regular physical activity display more desirable health outcomes across a variety of physical conditions. Similarly, participants in randomized clinical trials of physical-activity interventions show better health outcomes, including better general and health-related quality of life, better functional capacity and better mood states. SUMMARY: The studies have several implications for clinical practice and research. Most work suggests that exercise and physical activity are associated with better quality of life and health outcomes. Therefore, assessment and promotion of exercise and physical activity may be beneficial in achieving desired benefits across several populations. Several limitations were noted, particularly in research involving randomized clinical trials. These trials tend to involve limited sample sizes with short follow-up periods, thus limiting the clinical implications of the benefits associated with physical activity.

Journal Article↗
PubMed2005

Physical activity, global physical self-concept, and adolescent smoking.

BACKGROUND: Previous research supports a possible protective effect for physical activity against adolescent smoking. However, it is not clear whether the effect of physical activity on smoking is direct (e.g., time spent in physical activity) or indirect through another variable. One such variable is global physical self-concept (GPSC). Briefly, GPSC is a general perception of one's physical self, including appearance and physical activity competence. PURPOSE: This study tested a structural equation model of the relationship between physical activity and smoking, with direct effects from physical activity to smoking and an indirect effect through GPSC. METHODS: Participants were 983 12th graders taking part in a study of the biobehavioral predictors of adolescent smoking adoption. RESULTS: Controlling for covariates of adolescent smoking (e.g., peer smoking, alcohol use) and GPSC (e.g., body mass index, perceived physical appearance), physical activity had an indirect effect on smoking through its effects on GPSC, suggesting that the potential beneficial effects of physical activity on adolescent smoking may depend, in part, on GPSC. CONCLUSIONS: These results suggest that an adolescent's perception of the physical self may be one important factor to consider in youth smoking interventions. Further research is necessary to evaluate the longitudinal relationship between physical activity, GPSC, and smoking.

Adolescent↗
PubMed1994

Blood pressure, physical fitness and physical activity in 17-year-old Danish adolescents.

OBJECTIVE: To test the relationship between physical activity and physical fitness, and the relationship between these variables and the primordial risk factor blood pressure (BP). DESIGN: A cross-sectional study of all Danish pupils in the same grade at 'gymnasium' (the Danish upper secondary school). SETTING: Tests and questionnaires were administered by physical education and biology teachers according to a prescribed scheme. SUBJECTS: Study subjects were 13810 adolescents with a mean age of 17.1 years. Physical activity, smoking habits, and physical performance were measured in 4862 boys and 6573 girls. Blood pressure was measured in 2474 boys and 3535 girls. No difference was found in BP, physical activity and fitness variables between this group and a representative group of Danish school children at the same age. MAIN OUTCOME: Blood pressure and health-related physical performance such as strength, muscle endurance, flexibility and maximal oxygen uptake (VO2max) estimated from heart rate at submaximal workload were measured. Sports activity, other physical activity and smoking habits were assessed by questionnaires. RESULTS: There was a negative relationship between BP and VO2max up to the 50% percentile (50 ml min-1 kg-1) in boys and up to the upper 80-90% percentile (45 ml min-1 kg-1) in girls. In a multiple regression model with BP as dependent variable, VO2max related highly significant, also after adjustment for body weight and physical activity (P < 0.001). Other performance variables only explained a small part of the variance in BP. No relationship was found between BP and total physical activity or sports activity. CONCLUSION: In the adolescent population VO2max related negatively to BP after adjustment for body weight, physical activity, other fitness measures and sex, but physical activity or other fitness measures did not relate. Lower blood pressure was found with higher VO2max until levels of 50 and 45 ml min-1 kg-1 in boys and girls, respectively.

Adolescent↗
PubMed1997

The effects of a 2-year physical education program (SPARK) on physical activity and fitness in elementary school students. Sports, Play and Active Recreation for Kids.

OBJECTIVES: This study evaluated a health-related physical education program for fourth- and fifth-grade students designed to increase physical activity during physical education classes and outside of school. METHODS: Seven schools were assigned to three conditions in a quasi-experimental design. Health-related physical education was taught by physical education specialists or trained classroom teachers. Students from these classes were compared with those in control classes. Analyses were conducted on 955 students with complete data. RESULTS: Students spent more minutes per week being physically active in specialist-led (40 min) and teacher-led (33 min) physical education classes than in control classes (18 min; P < .001). After 2 years, girls in the specialist-led condition were superior to girls in the control condition on abdominal strength and endurance (P < .001) and cardiorespiratory endurance (P < .001). There were no effects on physical activity outside of school. CONCLUSIONS: A health-related physical education curriculum can provide students with substantially more physical activity during physical education classes. Improved physical education classes can potentially benefit 97% of elementary school students.

California↗
PubMed1996

[Changes in physical activity are not reflected in physical fitness of older teenagers. A 2-year follow-up study].

The study describes changes over two years in different physical fitness measures and the relationship between these changes and changes in physical activity. Maximal aerobic work capacity (watt(max)), functional strength, muscle endurance, agility and flexibility were measured in 259 randomly selected high school boys and girls 16.5 years of age and followed-up two years later, while they still attended school. Most physical fitness measures increased over time in boys, and in girls an increase was found in arm extensor strength and trunk extensor endurance, but watt(max) per kg body mass decreased. Changes in physical performance between 16 and 18 years of age seem to be very similar in different countries, despite differences in physical activity patterns and absolute level of performance. No change was found in time spent participating in physical activity or sports activity in either gender, but fewer girls participated in leisure-time sports at the second test (p < 0.001). Change in physical activity or sports activity did not relate to change in physical fitness level. The relationships between level of sports participation (competition, for health or none) and physical fitness measures at baseline and at the second test were weak or non-significant. Three explanations for the weak relationship between physical activity and fitness are suggested: a) part of the variability in fitness is explained by genetics, b) growth and hormonal changes, especially in boys, override the stimulus of training, and c) the physical fitness level in adolescents is so high that only physical activity at high relative intensity is supposed to have an effect on the fitness level.

Adolescent↗