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 127 records · Page 7Linked to original sources
PubMed1997

Correlation of bone density to strength and physical activity in young men with a low or moderate level of physical activity.

The objective of this study was to evaluate the relationship among bone mineral density (BMD), physical activity, muscle strength, and body constitution, in young men with a low or moderate level of physical exercise. Another aim was to investigate whether the head is unaffected by physical activity. The subjects consisted of 33 Caucasian healthy men, mean age 24.8 +/- 2.3 years. BMDs of the total body, lumbar spine (L2-L4), femoral neck, Ward's triangle and trochanter, humerus, and head were measured using dual-energy-X-ray absorptiometry (DXA). Bivariate correlations were measured among the different BMD sites and age, weight, height, body mass index (BMI), fat mass, lean body mass, amount of physical activity (hours/week), hamstrings strength, and quadriceps strength. Significant predictors were found for all BMD sites except the head. Using all these variables, only 6% of the variation in BMD of the head could be explained, whereas 46% (total body), 31% (humerus), 17% (lumbar spine), 38% (femoral neck, Ward's), and 41% could be explained for the trochanter. Physical activity and muscle strength were found to be independent significant predictors of BMD of the total body and the sites at the proximal femur. These results suggest that at the time of peak bone mass attainment, physical activity is an important predictor of the clinically relevant proximal femur in young men with a low or moderate level of physical activity. Furthermore, since head BMD was not related to the level of physical activity, we suggest that head BMD may be used as an internal standard, to control for selection bias, in studies investigating the effect of physical activity on bone mass.

Absorptiometry, Photon↗
PubMed1989

Association of physical activity with coronary risk factors and physical ability: twenty-year follow-up of a cohort of Finnish men.

The association of physical activity with coronary risk factors and self-reported physical ability was studied in a cohort of 331 healthy Finnish men aged 45-64 years at entry, representing the survivors of a 20-year longitudinal study from 1964 to 1984. Baseline physical activity was not significantly related to levels of coronary risk factors at subsequent 5-year, 10-year or 20-year follow-up examinations. The 72 who increased their physical activity during the study period smoked less at 20-year follow-up than those who remained sedentary (p = 0.03). No other significant associations between 20-year changes of physical activity and coronary risk factors were seen. Although baseline physical activity was not, physical activity and exercise at 20-year follow-up were positively related to indices of functional capacity assessed at the end of the study period, when the subjects had reached a mean age of 73 years. It is concluded from this long-term study that a relative increase of physical activity between middle and old age is associated with both less smoking and a maintained high level of physical ability.

Aged↗
PubMed1988

A mail survey of physical activity habits as related to measured physical fitness.

The associations of self-reported measures of physical activity from a mail survey with an objective measure of physical fitness were investigated. Respondents to a health status survey (n = 12,225), conducted in 1982 by the Institute for Aerobics Research in Dallas, TX, formed the population. From this group, males who also had a clinical examination within 60 days of the return of their questionnaire served as subjects. The study subjects (n = 375, mean age = 47.1 years) completed a maximal physical fitness assessment using a modified Balke protocol. The questionnaire included a section of inquiries concerning leisure time physical activity participation in which subjects were asked to quantitatively recall exercise participation for varying periods of time. Reported exercise participation values were converted to estimates of energy expenditure and combined into overall indices of physical activity participation. Multiple regression analyses were used to determine the individual contributions of the physical activity indices in predicting maximal treadmill performance (physical fitness). Significant predictors of physical fitness were age (beta = -0.34), an index of running, walking, and jogging participation (beta = 0.31), and the response to a question on frequency of sweating (beta = 0.35). The multiple correlation coefficient for these variables in predicting physical fitness was 0.65. These results indicate that exercise behavior can be accurately estimated in large populations by using simple questions in a mail survey.

Adult↗
PubMed1980

Role of physical therapists in physical activity programs in nursing homes: a survey.

A survey was conducted to help define the role of physical therapists in physical activity programs in nursing homes. Questionnaires were completed by 64 physical therapists working in nursing homes of 130--150 bed capacity. The major factors studied were employment status, work-time at the facility, interprofessional relationships, and available equipment and space. Of the respondents, 43.7 percent were involved in physical activity programs, the most common roles being staff instruction and consultation. Only a small percentage of the time was used for programs; most of the time was occupied with individual physical therapy treatment. The principal types of programs with physical therapist involvement were ambulation and gait training, bed exercises, and general group exercises. Equipment and space seemed adequate. Physical therapists were likely to be involved in physical activity programs if: 1) they were employed by the nursing homes, were paid on a salary basis, worked at the nursing homes full-time or nearly full-time, and did not work elsewhere; 2) such programs were mentioned during discussion of the work agreement; and 3) the coordinator of the physical activity programs was an occupational therapist or a nurse rather than an activities director or recreational therapist.

Aged↗
PubMed2007

[Trends in vigorous physical activity versus physical inactivity among 11-15 year olds from 1988 to 2002].

INTRODUCTION: The increasing prevalence of overweight and obesity among children and adolescents suggests a need to study the development in main predictors of obesity, like eating habits and physical activity. The objective was to describe self-reported vigorous physical activity versus physical inactivity among children and adolescents over a period of 14 years, 1988-2002. MATERIAL AND METHODS: The study population was the Health Behaviour in School-aged Children (HBSC) study among nationally representative samples of 11, 13 and 15 year old students in 1988, 1991, 1994, 1998, and 2002. The data collection used the standardised HBSC questionnaire which included items about vigorous physical activity (VPA) outside school hours per week. We defined physically inactivity as 0 hours of VPA per week and high activity as at least 7 hours of VPA per week. RESULTS: The prevalence of high activity was higher among boys than girls and increased by age. The prevalence of physically inactive students increased from 1988 to 2002, especially among the 15 year olds. The proportion of students with high activity decreased from 1988 to 2002, especially among the 15 year olds. CONCLUSION: A large proportion of children and adolescents do not comply with the national recommendations that children should be physically active at least 60 minutes per day. The physical activity level decreased from 1988 to 2002. There is a need for extraordinary efforts to increase physical activity among children and adolescents.

Adolescent↗
PubMedDate not supplied

Physical activity, exercise, and physical fitness: definitions and distinctions for health-related research.

"Physical activity," "exercise," and "physical fitness" are terms that describe different concepts. However, they are often confused with one another, and the terms are sometimes used interchangeably. This paper proposes definitions to distinguish them. Physical activity is defined as any bodily movement produced by skeletal muscles that results in energy expenditure. The energy expenditure can be measured in kilocalories. Physical activity in daily life can be categorized into occupational, sports, conditioning, household, or other activities. Exercise is a subset of physical activity that is planned, structured, and repetitive and has as a final or an intermediate objective the improvement or maintenance of physical fitness. Physical fitness is a set of attributes that are either health- or skill-related. The degree to which people have these attributes can be measured with specific tests. These definitions are offered as an interpretational framework for comparing studies that relate physical activity, exercise, and physical fitness to health.

Energy Metabolism↗
PubMed1986

Physical activity and physical demand on the job and risk of cardiovascular disease and death: the Framingham Study.

Cardiovascular events over 24 years of surveillance were examined in 1166 men participating in the Framingham Study, classified by physical demands of their work and by a 24-hour index of physical activity. Findings are based on 303 noncardiovascular, 220 coronary, and 325 cardiovascular deaths in men aged 45 to 64 years at time of physical activity assessment. For level of physical activity over 24 hours, there is a clear trend of improved overall, cardiovascular, and coronary mortality with increased level of physical activity at all ages, including the elderly. The effect is sustained with a more pronounced effect with the passage of time, despite presumed decrease in level of activity. The mortality benefits apply both in those with and without intervening overt cardiovascular disease, making it unlikely that the physical inactivity-mortality relationships reflects already existent myocardial damage. For physical demands of the job, there is only a suggestion (not statistically significant) of benefit for cardiovascular mortality including coronary deaths. In sharp contrast, noncardiovascular mortality was positively related to both physical demand of the job and 24-hour physical activity index.

Cardiovascular Diseases↗
PubMed1996

Physical activity, physical fitness, and all-cause and cancer mortality: a prospective study of men and women.

We studied physical fitness and physical activity in relation to all-cause and cancer mortality in a cohort of 7080 women and 25,341 men examined at the Cooper Clinic in Dallas, Texas, during 1970 to 1989. Physical fitness was assessed at baseline by a maximal treadmill exercise test, while physical activity was self-reported on the attendant health habits questionnaire. Both men and women averaged about 43 years of age at baseline (range, 20 to 88 years), and they were followed for approximately 8 years on average. Through the end of 1989, the women contributed 52,982 person-years of observation and incurred 89 deaths, including 44 deaths due to cancer. The men contributed 211,996 person-years and incurred 601 deaths, with 179 due to cancer. After adjustment for baseline differences in age, examination year, cigarette habit, chronic illnesses, and electrocardiogram abnormalities, we found a strong inverse association between risk of all-cause mortality and level of physical fitness in both men and women (P for trend < 0.001). Physically active men also were at lower risk of all-cause mortality than were sedentary ones (P for trend = 0.01). Among women, however, self-reported physical activity was not significantly related to risk of death from all causes. The risk of mortality from cancer declined sharply across increasing levels of fitness among men (P for trend < 0.001), whereas among women the gradient was suggestive but not significant (P for trend = 0.07). Physically active men also were at lower risk of death from cancer than were sedentary men (P for trend = 0.002), but among women physical activity was unrelated to cancer mortality.

Adult↗
PubMed1989

Age, physical activity, physical fitness, body composition, and incidence of orthopedic problems.

The incidence of orthopedic problems was examined in 5,582 men and women who attended the Cooper Clinic in Dallas, Texas between 1974 and 1982. The effects of age, physical activity, physical fitness, and body mass index (BMI) on the occurrence of these problems were examined using a proportional hazards approach. The expected risk of orthopedic problems per person-year was 0.045 for men and 0.046 for women. For men, physical fitness, BMI, and physical activity were associated with orthopedic problems, while for women, physical activity was the main predictor. Age was not a factor for either gender. The effect of change in physical fitness, physical activity, and BMI was examined in a subset of 2,325 persons with more than one visit to the clinic. For women, physical activity and a decrease in BMI were associated with orthopedic problems, while for men none of those factors were significant. Again, age was not a factor in either group. The absence of any age effect on the occurrence of problems suggests that with regard to orthopedic problems, moderate amounts of physical activity in generally healthy persons may be recommended without special consideration as to age.

Adolescent↗
PubMed1996

The epidemiology of physical activity and physical function in older people.

A primary goal of studies of successful aging is to identify the modifiable factors related to the plasticity of higher physical function; however, little is known about the relationship between habitual physical activity (especially that of lower- to moderate-intensity) and the maintenance of day-to-day functioning in older people. The purpose of this paper is to address the question of how patterns of physical activity translate into altered physical function among healthy older populations. In this paper, physical activity is classified as a behavior, whereas physical function is classified as performance, comprised of a series of increasingly integrated steps. Recent data from several epidemiologic studies suggest that physical activity is associated with the maintenance of more basic components of physical function, as well as with higher-order task or goal-oriented functions in healthy older people. Moreover, higher levels of physical activity appear to be associated with better functioning, even in those with already-existing chronic disease. Recent CDC/ACSM health recommendations call for incorporating at least 30 min of any activity into the daily schedule. Therefore, regular participation in activities of moderate intensity (such as walking, gardening, house/yard work) should be encouraged among the general older community.

Activities of Daily Living↗
PubMedDate not supplied

Physical activity, physical fitness, and Framingham 10-year risk score: the cross-cultural activity participation study.

PURPOSE: Although physical activity and physical fitness are inversely and causally associated with coronary heart disease (CHD) morbidity and mortality, available equations for estimating CHD risk do not include scores for activity or fitness. Therefore, this study evaluated the association of physical fitness and moderate-intensity physical activity with the 10-year Framingham CHD risk estimate. METHODS: Cross-sectional analyses were performed on data from 137 healthy middle-aged women (53.9 +/- 9.9 yr; 28.3 +/- 6.0 kg/m2). Health histories, body composition, blood pressure, and blood samples were obtained from a clinical examination. Levels of moderate (3-6 METS) intensity physical activity, expressed as MET-minutes/day of energy expenditure, were derived from multiple 24-hour physical activity records. Physical fitness was quantified as duration of a symptom-limited maximal treadmill exercise test. RESULTS: After adjustment for race, body mass index (BMI), and hormone replacement status, a graded reduction in the Framingham risk score was observed across low (5.8%), moderate (4.0%), and high (3.6%) fitness levels (P for trend = 0.009). Women in both the moderate and high fitness categories had a lower (P < 0.01) risk score compared with their low fit counterparts. Significant differences in risk were not seen among low (3.9%), moderate (4.9%), and high (4.4%) physical activity groups. The lack of association between the risk score by physical activity may have been due to the homogeneity of activity levels among participants. Our findings reinforce existing data that show enhanced levels of fitness are associated with lower risk for CHD.

Coronary Disease↗
PubMed1996

Physical activity, physical fitness, blood pressure, and fibrinogen in the Northern Ireland health and activity survey.

STUDY OBJECTIVE: To investigate the relationship between physical activity, physical fitness, blood pressure, and fibrinogen. DESIGN: This was a cross sectional population study using a two stage probability sample. SETTING: Northern Ireland. PARTICIPANTS: A sample of 1600 subjects aged 16-74 years from the population of Northern Ireland. MAIN OUTCOME MEASURES: Physical activity profile from computer assisted interview using the Allied Dunbar national fitness survey scales. Physical fitness using estimation of VO2 max by extrapolation from submaximal oxygen uptake while walking on a motor driven treadmill. Systolic and diastolic blood pressure measured with a Hawksley random zero sphygmomanometer. Measurement of fibrinogen using the Clauss method. MAIN RESULTS: There were significant relationships between both current and past activity and blood pressure. These were of a magnitude that would have been clinically significant, but for the fact that, with the exception of the relationship between habitual activity and diastolic pressure (p = 0.03) and past activity and systolic pressure (p = 0.03) in men, they were not sustained after adjustment for the effect of age using analysis of variance. After adjustment for other potentially confounding factors using multiple regression, there was an inverse relationship between systolic blood pressure and past activity in men, so that those with a life-time of participation compared with a life-time of inactivity had a lower systolic blood pressure of 6 mmHg (p < 0.05). There was a highly significant (p < 0.001) inverse association between both systolic and diastolic blood pressure and physical fitness (VO2 max) which was not sustained after adjustment for possible confounding factors. There were relationships between fibrinogen and highest recorded activity (p < 0.001), habitual activity (p < 0.01), and past activity (p < 0.01) in men but no significant relationship in women. The relationship between fibrinogen and activity was no longer sustained after adjustment for possible confounding factors. There was a highly significant (p < 0.001) inverse relationship with physical fitness using VO2 max. This relationship was sustained after adjustment for possible confounding factors in both men (p < 0.05) and women (p < 0.001). CONCLUSIONS: There was a relationship between physical activity, physical fitness, and blood pressure but the relationship was greatly influenced by age. A reduction of 6 mmHg in systolic blood pressure associated with past activity is of clinical significance and supports the hypothesis that physical activity is of benefit in reducing cardiovascular risk. There was a lower level of fibrinogen in those who were most active but this relationship was not significant after adjustment for possible confounding factors. There was also a lower level of fibrinogen those who were most fit (VO2 max) and this relationship persisted even after adjustment for possible confounding factors.

Adolescent↗
PubMed1997

A facilitator in self-reported perception of physical symptoms: the role of contingency between physical symptom and aversive event.

Perceptions of physical symptoms are influenced not only by the passive process of physiological stimuli but also by psychological factors such as the contingency between a physical symptom and an aversive event which we examined here in two experiments. 18 subjects in Exp. 1 and 14 subjects in Exp. 2 performed motor tasks. In the Physical condition, an aversive event was contingent on the physical symptom of 'racing heart' in Exp. 1, and on the symptom of 'overstraining shoulder muscles' in Exp. 2. In the Motor condition, an aversive event was contingent on the response of the 'disordered pace of motor tasks' in both experiments. Self-reported scores on attention to and perception of the physical symptoms under the Physical condition were higher than those under the Motor condition. However, there were no differences in the actual physical responses between the two conditions. These results suggest that a contingency between a physical symptom and an aversive event facilitates attention to and perception of the physical symptom.

Adolescent↗
PubMed2003

[Effect of physical training on growth and total cardiovascular and respiratory capacity in pupils from schools with different physical training programs].

AIM: Influence of physical exercise on psychomotor growth of children is well known. In present study we tried to evaluate influence of two different physical training programs carried out in schools, on parameters of cardiovascular and respiratory system. In addition we tried to evaluate the possible influence of diet on children growth. MATERIAL AND METHODS: Children from two schools were studied. Group I: 56 children (aged 10-12) from swimmers classes of the School of Sport Championship, who participated in 8 hours/week of physical exercises in addition to 10 hours/week of swimming exercises. Group II: 28 children (aged 10-12) from standard school, who participated in 3 hours/week of physical exercises. In both groups medical examination, spirometry, blood pressure and heart rate measurement, and diet analysis were performed at baseline and after maximal physical extortion. RESULTS AND CONCLUSIONS: 1. Spirometry analysis showed statistical differences between the groups, which were impaired in children from school with standard physical training program. 2. We observed worse adaptation to physical exercise of cardiovascular and respiratory system in from school with standard physical training program, as compared to children from group I. 3. No statistical differences in nutrition were shown between the groups. 4. Vitamins, iron and magnesium seem to have good influence on respiratory system adaptation to physical exercise. 5. In general, we observed better total capacity of cardiovascular and respiratory system in connected with better interest in correct nutrition in group I as compared to group II.

Blood Pressure↗