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PubMed2004

The effect of lifestyle modification on physical fitness and work ability in different workstyles.

It is generally considered that physical fitness is affected by daily life activities including leisure time activity and working time activity. The aim of this study is to investigate the effects of different levels of physical activity at work on physical fitness, analyze the effects of 12-week lifestyle modification outside of working hours on physical fitness, work satisfaction and subjective symptoms, and to consider the role of lifestyle modification in occupational health. Lifestyle modification, consisting of aerobic exercise and diet counseling, was conducted for 12 weeks. The data before and after the intervention from 49 male workers were obtained. Physical fitness such as exercise endurance, flexibility, agility, balance, muscular strength, muscular endurance, and muscular power was measured before and after the intervention. The subjects were asked to fill out questionnaires about their work activities, subjective complaints, and work satisfaction. Subjects were divided into active work group (n = 14) and sedentary work group (n = 35) for analysis according to their work activities. As for differences in physical fitness due to different levels of physical activity, the active work group had superior exercise endurance and balance compared to the sedentary work group. In addition, the sedentary work group tended to experience greater fatigue than the active work group. In the active work group, flexibility and muscular strength were significantly increased with lifestyle modification and, in the sedentary work group, exercise endurance, flexibility and muscular endurance were significantly improved while balance also showed a tendency to improve. In the sedentary work group, lifestyle modification resulted in reduced fatigue and stiff neck as well as an increased work satisfaction. In the active work group, no change was observed in complaints or work satisfaction, but improved physical fitness led to a reduction in subjective complaints and an increase in work satisfaction. The level of physical activity at work contributes to the physical fitness of the worker and the addition of aerobic exercise in the worker's leisure time improves physical fitness and thereby contributes to increased work ability regardless of differences in the level of physical activity at work.

Hand Strength↗
PubMed2001

Sociodemographic differences in patterns of sedentary and physically active behavior in older children and adolescents.

UNLABELLED: Numerous studies have found that involvement in moderate-intensity and strenuous activity has positive effects on health. This study considered the prevalence of different aspects of physical activity and sedentary behavior in 11-16-y-olds based on a representative national survey of 3270 Icelandic primary schoolchildren (91% response rate). All-day sedentary behavior was extremely rare (< 1%), and the vast majority (91%) were physically active (> or = 3 times per week) during school or leisure time, thanks largely to school physical education. Only 39% were physically active (> or = 3 times per week) during leisure time, and only 29% engaged in regular (> or = 3 times per week) leisure time strenuous exercise. Girls were more sedentary, less leisure time physically active, and less involved in leisure time strenuous exercise. Sedentary behavior increased and physically active behavior decreased with age, especially after early adolescence. However, there were no age differences in strenuous leisure time exercise. Upper-class students were less sedentary and more physically active during leisure time than working-class students. Finally, rural students were more sedentary during leisure time, and less physically active than students from urban areas. An interaction was found between age and residence when predicting leisure time physical activity, indicating that the inverse age-activity relationship in urban areas is partly reversed in rural areas. CONCLUSION: Compulsory school physical education frequently failed to translate into voluntary physical involvement. Sociodemographic differences in physical activity were greater during leisure time, than during school and leisure time combined.

Adolescent↗
PubMed2002

A retrospective analysis of ethics knowledge in physical therapy (1970-2000).

BACKGROUND AND PURPOSE: Purtilo, Guccione, and others have noted that increased clinical autonomy for physical therapists presents more complex ethical dilemmas. The body of literature examining physical therapy ethics, however, is relatively small and has not been analyzed. The primary purposes of this research were: (1) to use multiple perspectives to describe and analyze literature examining ethics in physical therapy from 1970 to 2000, (2) to develop a model to describe the evolution of knowledge of ethics in physical therapy during this period, and (3) to compare the proposed model with the evolutionary models proposed by Purtilo in physical therapy and by Pellegrino in bioethics. SAMPLE: The sample consisted of peer-reviewed journal articles cited in the MEDLINE or Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases between 1970 and 2000 or referenced in Ethics in Physical Therapy. METHODS: A two-phase mixed quantitative and qualitative method was used to analyze publications. In the quantitative phase, the author sorted publications into a priori categories, including approach to ethics, author, decade, country of publication, role of the physical therapist, and component of morality. During the qualitative phase of the research, the author analyzed and sorted the publications to identify common themes, patterns, similarities, and evolutionary trends. These findings were compared with the evolutionary models of Pellegrino and Purtilo. RESULTS: The 90 publications meeting inclusion criteria were predominantly philosophical, using the "principles" perspective; focused on the patient/client management role of the physical therapist; and addressed the moral judgment component of moral behavior. As predicted by Purtilo's model, the focus of identity evolved from self-identity to patient-focused identity, with increasing representation of societal identity. Recurrent themes included the need to further identify and clarify physical therapists' ethical dilemmas, the interrelationship between clinical and ethical decision making, and the changing relationship with patients. DISCUSSION AND CONCLUSION: Although knowledge of ethics grew steadily between 1970 and 2000, this retrospective analysis identified gaps in our current knowledge. Further research is needed to address the unique ethical problems commonly encountered in all 5 roles of the physical therapist; patient perspectives on ethical issues in physical therapy; variety in ethical approaches; factors affecting moral judgment, sensitivity, motivation, and courage; and cultural dimensions of ethical practice in physical therapy.

Ethics, Clinical↗
PubMed1994

Changes in physical activity are reflected in changes in fitness during late adolescence. A 2-year follow-up study.

The study describe changes over 2 years in different physical fitness measures and the relationship between these changes and changes in physical activity. Maximal aerobic work capacity (Wattmax), 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 2 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 Wattmax 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 of participation in physical activity or sports activity in either gender, but fewer girls participated in leisure-time sports at the 2nd 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 2nd 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↗
PubMed2000

Effect of physical activity on lipid levels in a population-based sample of men with and without the Arg192 variant of the human paraoxonase gene.

The prevalence of cardiovascular risk factors in Gerona, Spain, is high for the low myocardial infarction incidence and mortality rates in the province. Physical activity is a protective factor against coronary heart disease. We investigated whether the genetic variants Q and R of the paraoxonase Gln-Arg 192 polymorphism were involved in different responses of lipids to physical activity. Serum triglycerides, HDL-cholesterol concentrations, and the paraoxonase Gln-Arg 192 polymorphism were determined in 262 men randomly selected from a representative population sample in a cross-sectional study conducted in Gerona, Spain. The Minnesota Leisure Time Physical Activity Questionnaire was used to assess energy expenditure in leisure time physical activity. No differences were found in lipid levels among tertiles of physical activity distribution in subjects with the QQ genotype. However, R carriers showed a significant decreasing trend in triglyceride levels and in log-triglyceride-to-HDL-cholesterol ratio and a significant increasing trend in HDL-cholesterol concentration with the amount of physical activity. R carriers included in the low tertile of physical activity distribution had HDL-cholesterol levels significantly lower than those of QQ homozygous men in the same physical activity category (1.04 mmol/L vs. 1.22 mmol/L, P = 0.024). R carriers of the higher tertile of physical activity distribution showed the most favorable lipid profile in this genetic group. A statistically-significant interaction between paraoxonase genotypes and physical activity was observed for log triglycerides (P = 0.018), HDL-cholesterol concentration (P = 0.017), and log triglyceride-to-HDL-cholesterol ratio (P = 0.008). The beneficial association of the amount of physical activity and lipid traits found in men with the R allele suggests that this population subgroup needs to be physically active to achieve a favorable lipoprotein phenotype similar to that observed in QQ homozygous men.

Adult↗
PubMed1989

Biological age versus physical fitness age.

A population of healthy middle-aged (n = 69) and elderly men (n = 12), who participated in a health promotion program, was studied to determine whether really physically fit individuals are in good biological condition, and also whether improvement of physical fitness in the middle-aged and the elderly reduces their "rate of aging". Biological and physical fitness ages of the individuals studied were estimated from the data for 18 physiological function tests and 5 physical fitness tests, respectively, by a principal component model. The correlation coefficient between the estimated biological and physical fitness ages was 0.72 (p less than 0.01). Detailed analyses of the relationship between the estimated biological and physical fitness ages revealed that those who manifested a higher ("older") physical fitness age did not necessarily have a higher biological age, but those who manifested a lower ("younger") physical fitness age were also found to have a lower biological age. These results suggested that there were considerable individual variations in the relationship between biological condition and physical fitness among individuals with an old physical fitness age, but those who were in a state of high physical fitness maintained a relatively good biological condition. The data regarding the elderly men who had maintained a regular exercise program indicated that their estimated biological ages were considerably younger than the expected values. This might suggest that in older individuals regular physical activity may provide physiological improvements which in turn might reduce "the rate of aging".

Adult↗
PubMed1998

Changes in physical activity beliefs and behaviors of boys and girls across the transition to junior high school.

PURPOSE: This longitudinal study investigated gender-specific changes in physical activity beliefs and behaviors across the elementary to junior high school transition. METHODS: Physical activity beliefs and behaviors were measured in a cohort of 132 racially diverse youth during the year prior to and following the transition. Questionnaires assessed variables hypothetically linked to activity. Physical activity was monitored with the Child/Adolescent Activity Log. RESULTS: Gender differences in physical activity beliefs emerged. Across the transition, boys reported decreased efficacy, social support, and expectations (norms) to be physically active. Although girls also reported decreased social support for physical activity, they further reported exposure to fewer active role models and were less likely to perceive that the benefits of regular activity out-weighed the barriers following the transition. Gender differences in activity levels were apparent, with girls being less active than boys. Despite changes in physical activity beliefs across the school transition, no significant changes in actual level of activity occurred over this period. Although beliefs were significantly related to behaviors in the domain of physical activity, pretransition activity level was the best predictor of posttransition activity level. CONCLUSIONS: These data indicate that physical activity beliefs of adolescents change over the school transition. These changes are significantly, but not highly, related to level of physical activity. Future research should explore the influences of activity-related affect and social and physical contexts on physical activity across adolescence.

Adolescent↗
PubMed2000

A fifteen-year longitudinal study in young adults on the relation of physical activity and fitness with the development of the bone mass: The Amsterdam Growth And Health Longitudinal Study.

Although positive effects of physical activity are often reported, there are still uncertainties about the type, intensity, duration, and frequency of these activities that are most effective for (re)modeling bone mass during youth. In the Amsterdam Growth and Health Longitudinal Study, daily physical activity and fitness were monitored from age 13 to 29 years in a group of 182 males and females. At a mean age of 28 years, bone mineral density (BMD) was measured at three sites with dual X-ray absorptiometry (DXA): in the lumbar region (lumbar BMD), the femoral neck (hip BMD), and the distal radius (wrist BMD). Physical activity (PA) was estimated from a cross-check activity interview taking in consideration all daily physical activities during the last 3 months; PA was scored in two different ways: (1) metabolic physical activity score (METPA) by weighting the intensity (multiples of basic metabolic rate [METs]) and duration (minutes per week); and (2) mechanic physical activity score (MECHPA) by weighting the peak strain (ground reaction forces as multiples of body mass) irrespective of frequency and duration of the physical activities. Physical fitness was measured with a neuromotor fitness test (composite of six strength, flexibility, and speed tests) and as cardiopulmonary fitness (maximal oxygen uptake). The physical activity and fitness scores were calculated over two age periods: during adolescence (13-16 years) and during adulthood (21-27 years). The standardized regression coefficients (corrected for gender, biological age, body composition, and calcium intake) show that weight, physical activity (both METPA and MECHPA), and neuromotor fitness during adolescence and in young adulthood are significantly and positively related with the lumbar BMD (beta = 0. 11-0.40) and hip BMD (beta = 0.18-0.26), measured at the mean age of 28 years. This was not the case for cardiorespiratory fitness. No significant correlations at all are found with wrist BMD, a bone site that is less involved in physical activity and fitness. It can be concluded that daily physical activity during adolescence and in the young adult period is significantly related to the BMD at the lumbar spine and femoral neck at age 28 of males and females. Only neuromotor fitness and not cardiopulmonary fitness during adolescence and young adulthood is related to the BMD of males and females at age 28 years.

Adolescent↗
PubMed2004

Physical activity after cancer: physiologic outcomes.

Physical activity has many and varied effects on the human body. The physiologic effects of physical activity and exercise in persons with cancer have been largely unstudied. Cancer patients as a group are at risk for diseases and conditions related to lack of physical activity. In persons with cancer, exercise has been shown to improve fitness and physical functioning, reduce fatigue, and modestly decrease weight and body fat. The effects of physical activity on prognosis, however, are unknown. In persons without cancer, exercise has beneficial effects on the cardiovascular and endocrine systems, reducing risk of cardiovascular disease, cerebrovascular disease, and diabetes. Increased physical activity reduces risk for several common cancers, which is relevant to cancer survivors who are at increased risk for new primary cancers. Additional benefits of physical activity include improvements in fitness, muscular-skeletal problems including arthritis symptoms, immune system function, cognition and sleep. Risks of increased physical activity in cancer patients and survivors have not been defined, but could be expected to include musculo-skeletal injuries, and a small increased risk in sudden death with vigorous exercise and serious accidents with some sports. The effect of physical activity on survival from cancer is unknown, but physical activity might improve prognosis through beneficial effect on cancer biomarkers and energy balance, as well as decreasing risk for cardiovascular disease, an important cause of death for many cancer survivors. The long-term benefits and risks of physical activity in cancer patients and survivors are unknown. Nevertheless, increasing physical activity is probably beneficial and safe in the majority of cancer survivors.

Body Mass Index↗
PubMed1988

Physical therapy care for low back pain. Monitored program of first-contact nonphysician care.

We studied the process and outcomes of physical therapist management of 107 patients with low back pain at a walk-in clinic. Sixty-seven patients with low back pain concurrently were assigned randomly to internists at the clinic. Physicians and physical therapists recorded baseline clinical data and management plans on standard check lists. Physical therapists used a validated algorithm that directed diagnostic evaluations and physician consultations, but all other physical therapist treatment decisions were unconstrained. Patients in the physical therapist and physician groups did not differ significantly. Physical therapists referred more patients to the physical therapy department than did physicians but recommended muscle relaxants, prescription analgesics, and bed rest less frequently. The occurrence of new symptoms, duration of symptoms, and duration of activity limitations were similar between the physician and physical therapy patient groups at a one-month follow-up examination. Physical therapist-managed patients expressed greater satisfaction than physician-managed patients with several aspects of their care. The percentage of functional improvement for highly dysfunctional patients was significantly greater for the physical therapist-managed patients than for the physician-managed patients. The implications of a physical therapist first-contact care program for health service organizations, health care policy, physical therapist training, and credentialing are discussed.

Adolescent↗
PubMed2001

Physical fitness and activity as separate heart disease risk factors: a meta-analysis.

OBJECTIVE: Public health policies for physical activity presume that the greatest health benefits are achieved by increasing physical activity among the least active. This presumption is based largely on studies of cardiorespiratory fitness. To assess whether studies of cardiorespiratory fitness are germane to physical activity guidelines, we compared the dose-response relationships between cardiovascular disease endpoints with leisure-time physical activity and fitness from published studies. DATA SOURCES: Twenty-three sex-specific cohorts of physical activity or fitness (representing 1,325,004 person-years of follow-up), cited in Tables 4-1 and 4-2 of the Surgeon General's Report. DATA SYNTHESIS: Relative risks were plotted as a function of the cumulative percentages of the samples when ranked from least fit or active, to most fit or active. To combine study results, a weighted average of the relative risks over the 16 physical activity or seven fitness cohorts was computed at every 5th percentile between 5 and 100%. The analyses show that the risks of coronary heart disease or cardiovascular disease decrease linearly in association with increasing percentiles of physical activity. In contrast, there is a precipitous drop in risk occurring before the 25th percentile of the fitness distribution. As a consequence of this drop, there is a significant difference in the risk reduction associated with being more physically active or physically fit (P < or = 0.04). CONCLUSIONS: Being unfit warrants consideration as a risk factor, distinctly from inactivity, and worthy of screening and intervention. Formulating physical activity recommendations on the basis of fitness studies may inappropriately demote the status of physical fitness as a risk factor while exaggerating the public health benefits of moderate amounts of physical activity.

Activities of Daily Living↗
PubMed2003

The effect of a fear-avoidance-based physical therapy intervention for patients with acute low back pain: results of a randomized clinical trial.

STUDY DESIGN: A randomized clinical trial with 4-week and 6-month follow-up periods. OBJECTIVE: To compare the effect of a fear-avoidance-based physical therapy intervention with standard care physical therapy for patients with acute low back pain. SUMMARY OF BACKGROUND DATA: The disability reduction strategy of secondary prevention involves providing specific treatment for patients that are likely to have chronic disability from low back pain. Previous studies have indicated that elevated fear-avoidance beliefs are a precursor to chronic disability from low back pain. However, the effectiveness of physical therapy intervention based on a fear-avoidance model is unknown. METHODS: Sixty-six consecutive patients referred to physical therapy with low back pain of less than 8 weeks' duration were randomly assigned to receive fear-avoidance-based physical therapy (n = 34) or standard care physical therapy (n = 32). The intervention period lasted 4 weeks for this study. Disability, pain intensity, and fear-avoidance beliefs measures were recorded before and after treatment. A 6-month follow-up of the same measures was obtained by mail. RESULTS: An intention-to-treat principle (last value forward) was used for data analyses that tested the primary and secondary hypotheses. The prediction of disability at 4 weeks and 6 months after treatment was significantly improved by considering the interaction between the type of treatment and the initial level of fear-avoidance beliefs. Both groups had significant within group improvements for disability and pain intensity. The fear-avoidance treatment group had a significant improvement in fear-avoidance beliefs, and fear-avoidance beliefs about physical activity were significantly lower than the standard care group at 4 weeks and 6 months after treatment. CONCLUSION: Patients with elevated fear-avoidance beliefs appeared to have less disability from fear-avoidance-based physical therapy when compared to those receiving standard care physical therapy. Patients with lower fear-avoidance beliefs appeared to have more disability from fear-avoidance-based physical therapy, when compared to those receiving standard care physical therapy. In addition, physical therapy supplemented with fear-avoidance-based principles contributed to a positive shift in fear-avoidance beliefs.

Acute Disease↗
PubMed1997

Identifying hospitalized older patients at varying risk for physical performance decline: a new approach.

OBJECTIVE: A classification tree analysis identifies patient groups at varying risk for decline in physical performance 1 year after hospitalization. DESIGN: Prospective cohort study. SETTING: Tertiary care VAMC. PARTICIPANTS: A total of 507 acutely ill hospitalized male veterans aged 65 years and older. MEASUREMENTS: Eighteen admission characteristics were considered as potential predictors: demographic data, medical diagnoses, functional status (e.g., ADL and IADL), geriatric conditions (e.g., incontinence, vision impairment, weight change), mental status, depression, and physical functioning (measured by self-report (MOS-PFR) and the Physical Performance and Mobility Examination (PPME)). Outcome measure was change in PPME status at 12-months post-admission. RESULTS: Patients with the greatest risk for decline had both high baseline physical performance (PPME > or = 9) and at least moderate self-report limitations on physical functioning (MOS-PFR < or = 36, mean = 30.8). Patients with the lowest risk of decline had impaired baseline physical performance (PPME < or = 8) but fewer self-report limitations on physical functioning (MOS-PFR > or = 31, mean = 37.4) and two or less geriatric conditions. CONCLUSIONS: The predictive role of self-report functioning suggests that perception of the impact of health on one's own physical functioning is associated with future performance. The number of geriatric conditions is also an important predictor of physical performance change. By identifying patient risk groups based on geriatric conditions, physical performance, and self-report physical functioning, future targeting strategies may improve physical performance outcomes for hospitalized older adults.

Aged↗
PubMed2000

Respiratory fitness, free living physical activity, and cardiovascular disease risk in older individuals: a doubly labeled water study.

The objective of this study was to examine the importance of cardiorespiratory fitness vs. physical activity energy expenditure on selected cardiovascular disease risk factors in older individuals. One hundred and seventeen older individuals, 53 men (68 +/- 9 yr) and 63 women (67 +/- 7 yr), participated in the study. This cohort was divided into 4 groups: 1) high cardiorespiratory fitness and high physical activity, 2) high cardiorespiratory fitness and low physical activity, 3) low cardiorespiratory fitness and high physical activity, and 4) low cardiorespiratory fitness and low physical activity. Cardiorespiratory fitness (VO2max) was determined from a graded exercise test, physical activity energy expenditure was measured by doubly labeled water and indirect calorimetry, body composition was determined by dual energy x-ray absorptiometry, and dietary practices were determined by a 3-day recall. Cardiorespiratory fitness exerted greater effects on the cardiovascular disease risk profile than physical activity. That is, older individuals with higher levels of cardiorespiratory fitness, regardless of their physical activity levels, showed lower levels of fasting insulin (P < 0.01), triglycerides (P < 0.05), total cholesterol (P < 0.05), total to high density lipoprotein cholesterol ratio (P < 0.05), low density lipoprotein (P < 0.05), and lower waist circumference (P < 0.01). Moreover, individuals with a high cardiorespiratory fitness but low physical activity energy expenditure displayed a more favorable cardiovascular disease risk profile than individuals with low cardiorespiratory fitness and high physical activity energy expenditure. The results suggest that higher levels of cardiorespiratory fitness have greater cardioprotective effects than higher levels of free living physical activity in older individuals. Although these findings do not discount the health benefits of being physically active, it is possible that greater emphasis should be placed on aerobic exercise to increase cardiorespiratory fitness in the elderly.

Abdomen↗
PubMed2003

Validation of a new self-report instrument for measuring physical activity.

PURPOSE: Development and validation of a physical activity scale for measuring physical activity in 24 h of sports, work, and leisure time on an average weekday. METHODS: For development of the physical activity scale, 2500 randomly selected Danish men and women between the age of 20 and 60 were contacted by mail and asked to select frequent and relevant physical activities from a number of activities of known MET intensity. The activities were included in the physical activity scale, organized in nine different MET levels ranging from sleep/rest (0.9 METs) to high-intensity physical activities (>6 METs). Face validity of the physical activity scale was explored through interviews with 10 volunteer men and women. Concurrent validity was assessed against 4 d of accelerometry (CSA 7164) and physical activity diary in 40 volunteer men and women between 20 and 60 yr of age. RESULTS: The correlation between the activity scale and the diary was high (r = 0.74, P = 0.000), whereas correlation between the activity scale and accelerometer measurements was poor (r = 0.20, NS). The physical activity scale MET-time was systematically higher than average MET-time estimated from the diary, and the difference increased with increasing total MET-time. CONCLUSION: The physical activity scale appears to be a simple and valid alternative to measuring physical activity by diary in adult sedentary to moderately active Danes. The scale encompasses work, leisure time, and sports activity in one measure; it is easy to administer, and it provides detailed information on different activity levels as well as a single measure of the total amount of physical activity on an average weekday.

Adolescent↗
PubMed2003

Body mass index, but not physical activity, is associated with C-reactive protein.

UNLABELLED: Elevated high-sensitivity c-reactive protein (hs-CRP) is associated with increased risk of future first and recurrent coronary events and has been associated with both high body mass index (BMI) and low physical activity in cross sectional studies. PURPOSE: To longitudinally examine the effects of BMI and both current and previous-year physical activity on hs-CRP in healthy men and women (N = 109). METHODS: BMI and hs-CRP were measured five times (baseline and quarterly) over 1 yr. Current physical activity was assessed 12-15 times during the study via 24-h recall. Previous-year physical activity was assessed using the Baecke questionnaire at baseline. RESULTS: Mean BMI and hs-CRP were unchanged over the course of the study, but current physical activity increased on visit 3. Average hs-CRP was not related to average current physical activity or to natural changes in current physical activity across the five visits. Additionally, current physical activity on any given visit was not associated with hs-CRP on the following visit. When current physical activity, BMI, age, gender, and smoking were included in the statistical model, only BMI was significantly related to hs-CRP (P < 0.001). Average hs-CRP was significantly correlated with average BMI (r = 0.50; P < 0.001) but was not related to previous-year (Baecke) physical activity levels (r = 0.02; P = 0.89). When subjects were grouped by BMI (<25 kg.m-2, 25-29.9 kg x m-2, >30 kg x m-2) hs-CRP was significantly greater in obese (3.2 +/- 1.9 mg.L-1) and overweight (2.1 +/- 1.7 mg x L-1) than normal weight (1.1 +/- 1.0 mg.L-1) subjects (ANOVA P < 0.05). Current physical activity was similar between the three BMI groups at all times, and was unrelated to hs-CRP in all groups, throughout the study period. CONCLUSION: These data indicate that BMI, but not previous-year or current physical activity, predicts hs-CRP.

Adult↗
PubMed2005

Enjoyment mediates effects of a school-based physical-activity intervention.

PURPOSE: The study evaluated whether targeted changes in factors influencing enjoyment of physical education (PE), physical activity enjoyment, and self-efficacy beliefs about participating in physical activity mediated the effect of the Lifestyle Education for Activity Program (LEAP) intervention on participation in physical activity. METHODS: High schools (N=24) paired on enrollment size, racial composition, urban or rural location, and class structure were randomized into control (N=12) or experimental (N=12) groups. Of the 4044 girls enrolled and eligible, 2087 (51.6%) participated in the measurement component of the study. There were 1038 girls in the control group and 1049 girls in the experimental group. INTERVENTION: LEAP was a comprehensive school-based intervention emphasizing changes in instruction and school environment designed to increase physical activity among black and white adolescent girls. It was organized according to the Coordinated School Health Program and included a PE component with core objectives of promoting enjoyment of PE, physical activity enjoyment, and self-efficacy. RESULTS: Latent variable structural equation modeling indicated that: 1) the intervention had direct, positive effects on physical activity and factors influencing enjoyment of PE, which subsequently explained the effects of increased physical activity enjoyment and self-efficacy on increased physical activity; and 2) an additional, indirect effect of physical activity enjoyment on physical activity operated by an influence on self-efficacy. CONCLUSIONS: Increases in enjoyment partially mediated the positive effect of the LEAP intervention. To our knowledge, we have provided the first experimental evidence from a randomized controlled trial linking increased enjoyment with increased physical activity among black and white adolescent girls.

Adolescent↗
PubMed2001

Physical activity and bone measures in young children: the Iowa bone development study.

OBJECTIVES: Physical activity has a beneficial effect on bone development in circumpubertal children, although its effect on younger children is uncertain. In this cross-sectional study, we examined associations between physical activity and bone measures in 368 preschool children (mean age: 5.2 years, range: 4-6 years). DESIGN: Physical activity was measured using 4-day accelerometry readings, parental report of children's usual physical activity, and parental report of children's hours of daily television viewing. Total body and site-specific bone mineral content and area bone mineral density (BMD) were measured by dual energy radiograph absorptiometry. RESULTS: After adjustment for age and body size, accelerometry measures of physical activity and parental report of usual physical activity were consistently and positively associated with bone mineral content and BMD in both boys and girls (r = 0.15-0.28). Television viewing was inversely associated with hip BMD in girls (r = -0.15). The proportion of variance in bone measures explained by physical activity in linear regression models ranged from r(2) = 1.5% to 9.0%. In all of these models except total body BMD, at least 1 and often several of the physical activity variables entered as independent predictors. Activity variables most likely to enter the regression models were vigorous physical activity (as determined by accelerometry) and parental ranking of child's usual physical activity. CONCLUSIONS: Findings indicate that there are statistically significant and, perhaps important, associations between physical activity and bone measures during early childhood, well ahead of the onset of peak bone mass. This would suggest that intervention strategies to increase physical activity in young children could contribute to optimal bone development.

Absorptiometry, Photon↗