The association between physical activity,cardiorespiratory fitness and self-rated health

Objective

To investigate the joint association between self-reported physical activity as well as cardiorespiratory fitness and self-rated health among healthy women and men.

Method

Data from 10,416 participants in The Danish Health Examination Survey 2007–2008 which took part in 13 Danish municipalities were analyzed. Leisure time physical activity level and self-rated health were based on self-reported questionnaire data. Optimal self-rated health was defined as “very good” or “good” self-rated health. Cardiorespiratory fitness (mL O₂·min^− 1·kg^− 1) was estimated from maximal power output in a maximal cycle exercise test.

Results

A strong dose–response relation between cardiorespiratory fitness and self-rated health as well as between physical activity level and self-rated health among both women and men was found. Within categories of physical activity, odds ratios for optimal self-rated health increased with increasing categories of cardiorespiratory fitness, and vice versa. Hence, participants who were moderately/vigorously physically active and had a high cardiorespiratory fitness had the highest odds ratio for optimal self-rated health compared with sedentary participants with low cardiorespiratory fitness (odds ratio = 12.2, 95% confidence interval: 9.3–16.1).

Conclusion

Although reluctant to conclude on causality, this study suggests that an active lifestyle as well as good cardiorespiratory fitness probably increase self-rated health.     

Leisure-time physical activity, cardiorespiratory fitness and feelings of hopelessness in men

Background  

Leisure-time physical activity (LTPA) and cardiorespiratory fitness contribute to mental health. Hopelessness has been linked to impaired mental health, cardiovascular events and mortality. Previous studies have focused on physical exercise and depression. We examined the associations of LTPA and cardiorespiratory fitness with feelings of hopelessness.     

Rural-urban differences in physical activity, physical fitness, and overweight prevalence of children.

CONTEXT: The increasing prevalence of overweight in youth has been well chronicled, but less is known about the unique patterns and risks that may exist in rural and urban environments. A better understanding of possible rural-urban differences in physical activity profiles may facilitate the development of more targeted physical activity interventions. METHODS: Participants (1,687 boys; 1,729 girls) were recruited from fourth, fifth, and sixth grade classes in schools from urban areas, small cities, and rural areas. Multilevel modeling analysis was used to examine rural-urban differences in physical activity and prevalence of overweight. Physical activity was assessed by self-report and body mass index was calculated from measured height and weight. FINDINGS: Prevalence of overweight was higher among rural children (25%; P<.001) than children from urban areas (19%) and small cities (17%). Urban children were the least active overall (Cohens' d=-0.4), particularly around lunchtime while at school (d=-0.9 to -1.1). Children from small cities reported the highest levels of physical activity. CONCLUSIONS: The results of this study suggest there are rural-urban differences in children's prevalence of overweight and physical activity even within a fairly homogenous Midwestern state.     

The association between work performance and physical activity, cardiorespiratory fitness, and obesity

The purpose of this study was to test the association between lifestyle-related modifiable health risks (physical activity, cardiorespiratory fitness, and obesity) and work performance. Data were obtained from 683 workers. Dependent variables included number of work loss days, quantity and quality of work performed, overall job performance, extra effort exerted, and interpersonal relationships. Results indicated that higher levels of physical activity related to reduced decrements in quality of work performed and overall job performance; higher cardiorespiratory fitness related to reduced decrements in quantity of work performed, and a reduction in extra effort exerted to perform the work; obesity related to more difficulty in getting along with coworkers; severe obesity related to a higher number of work loss days. It is concluded that lifestyle-related modifiable health risk factors significantly impact employee work performance.     

Association among physical activity level, cardiorespiratory fitness, and risk of musculoskeletal injury

To help public health practitioners promote physical activities with a low risk of injury, this study determined the relation among type and duration of physical activity, cardiorespiratory fitness, and musculoskeletal injury in a sample of adults enrolled in the Aerobics Center Longitudinal Study. Subjects included 4,034 men and 967 women who underwent a baseline physical examination between 1970 and 1985 and who returned a mailed follow-up survey in 1986. At baseline, a treadmill graded exercise test was used to measure cardiorespiratory fitness. At follow-up, subjects reported injuries and type and duration of physical activity in the preceding 12 months. Polytomous logistic regression was used to estimate the association among physical activity type and duration, cardiorespiratory fitness, and injury. The risk of sustaining an activity-related injury increased with higher duration of physical activity per week and cardiorespiratory fitness levels. Results suggest that cardiorespiratory fitness may be a surrogate for unmeasured components of physical activity, such as exercise intensity. Among walkers, increasing duration of activity per week was not associated with an increased risk of injury. Results suggest that, for most adults, walking is a safe form of physical activity associated with a lower risk of injury than running or sport participation.     

Physical fitness and physical activity in obese and nonobese Flemish youth

OBJECTIVE: To assess different aspects of physical fitness and physical activity in obese and nonobese Flemish youth. RESEARCH METHODS AND PROCEDURES: A random sample of 3214 Flemish schoolchildren was selected and divided into an "obese" and "nonobese" group based on body mass index and sum of skinfolds. Physical fitness was assessed by the European physical fitness test battery. Physical activity was estimated by a modified version of the Baecke Questionnaire. RESULTS: Obese subjects had inferior performances on all tests requiring propulsion or lifting of the body mass (standing-broad jump, sit-ups, bent-arm hang, speed shuttle run, and endurance shuttle run) compared with their nonobese counterparts (p < 0.001). In contrast, the obese subjects showed greater strength on handgrip (p < 0.001). Both groups had similar levels of leisure-time physical activity; however, nonobese boys had a higher sport index than their obese counterparts (p < 0.05). DISCUSSION: Results of this study show that obese subjects had poorer performances on weight-bearing tasks, but did not have lower scores on all fitness components. To encourage adherence to physical activity in obese youth, it is important that activities are tailored to their capabilities. Results suggest that weight-bearing activities should be limited at the start of an intervention with obese participants and alternative activities that rely more on static strength used.     

Participation in physical activity among normal- and overweight Hispanic and non-Hispanic white adolescents

BACKGROUND: The purpose of this study was to determine the relation between weight status and participation in physical activity (PA) among Hispanic and non-Hispanic white (NHW) adolescent boys and girls. METHODS: In this cross-sectional study, height and weight were measured and a modified 2001 Youth Risk Behavior Survey was administered to 1,302 Hispanic and NHW adolescents, aged 14-17 years, attending high school in Nueces County, Texas. Linear regression analysis was used to assess the relation between weight status (normal weight or "at risk for overweight and overweight" [AR&O]) and PA, including moderate PA, vigorous PA, strength training, participation in team sports, and TV viewing, according to gender and ethnicity. RESULTS: Thirty-eight percent of adolescents were AR&O, including 32% and 48% of Hispanic girls and boys, respectively, and 22% and 35% of NHW girls and boys, respectively. As expected, boys reported participating in more PAs than girls. Compared with NHW girls, both normal weight and AR&O Hispanic girls reported significantly fewer bouts of moderate activity, less involvement in team sports, and more time watching TV. Normal weight boys reported participating in significantly more vigorous activity than those who were AR&O. Hispanic boys reported more strength training than NHWs; however, they watched significantly more hours of TV than NHW boys. CONCLUSIONS: Hispanic and NHW high school students reported participation in different PAs; this information may be useful for planning health and physical education curriculum.     

The impact of state physical education requirements on youth physical activity and overweight

To combat childhood overweight in the US, which has risen dramatically in the past three decades, many medical and public health organizations have called for students to spend more time in physical education (PE) classes. This paper is the first to examine the impact of state PE requirements on student PE exercise time. It also exploits variation in state laws as quasi-natural experiments in order to estimate the causal impact of PE on overall student physical activity and weight. We study nationwide data from the Youth Risk Behavior Surveillance System for 1999, 2001, and 2003 merged with data on state minimum PE requirements from the 2001 Shape of the Nation Report.We find that high school students with a binding PE requirement report an average of 31 additional minutes per week spent physically active in PE class. Our results also indicate that additional PE time raises the number of days per week that girls report having exercised vigorously or having engaged in strength-building activity. We find no evidence that PE lowers BMI or the probability that a student is overweight.We conclude that raising PE credit requirements may make girls more physically active overall but there is not yet the scientific base to declare raising PE requirements an anti-obesity initiative for either boys or girls.     

Work ability, physical activity, and cardiorespiratory fitness: 2-year results from Project Active

An adequate level of physical activity may maintain or promote work ability in aging workers. Project Active is a randomized trial comparing a Lifestyle physical activity program with a Structured exercise program in sedentary but healthy adults aged 35 to 60 years. Subjects in both groups received 6 months of intensive intervention followed by 18 months of active follow-up. The total number of subjects was 235, from which 80 subjects participated in the work ability assessment. Primary outcome measures were energy expenditure (kcal.kg-1.day-1), cardiorespiratory fitness (peak oxygen uptake in ml.min-1.kg-1), and the Work Ability Index. At 6 months, daily energy expenditure had increased significantly over baseline (mean +/- SD, from 33.0 +/- 0.9 to 34.4 +/- 1.8 kcal.kg-1.day-1) and was maintained over baseline at 24 months (34.0 +/- 2.5 kcal.kg-1.day-1). The significant increase in energy expenditure was observed particularly in moderate levels of activity. The average percentage of body fat was significantly higher at baseline compared with 6 months and 24 months. Peak oxygen uptake increased from baseline significantly during the first 6 months (from 29.6 +/- 5.7 to 30.6 +/- 6.3 ml.min-1.kg-1) and decreased to the baseline level (29.1 +/- 5.5 ml.min-1.kg-1) at 24 months. At baseline, the average Work Ability Index was 44.2 +/- 4.0, and it remained unchanged at 6 months (44.4 +/- 3.9) and at 24 months (44.2 +/- 3.1). In conclusion, a 2-year physical activity intervention increased daily energy expenditure, reduced body fat, and maintained peak oxygen uptake in healthy, middle-aged, sedentary subjects. The average Work Ability Index score at baseline was excellent and did not change during the 2-year physical activity interventions.     

Effects of interventions in health care settings on physical activity or cardiorespiratory fitness

Introduction:This paper reviews studies of physical activity interventions in health care settings to determine effects on physical activity and/or fitness and characteristics of successful interventions.Methods: Studies testing interventions to promote physical activity in health care settings for primary prevention (patients without disease) and secondary prevention (patients with cardiovascular disease [CVD]) were identified by computerized search methods and reference lists of reviews and articles. Inclusion criteria included assignment to intervention and control groups, physical activity or cardiorespiratory fitness outcome measures, and, for the secondary prevention studies, measurement 12 or more months after randomization. The number of studies with statistically significant effects was determined overall as well as for studies testing interventions with various characteristics.Results: Twelve studies of primary prevention were identified, seven of which were randomized. Three of four randomized studies with short-term measurement (4 weeks to 3 months after randomization), and two of five randomized studies with long-term measurement (6 months after randomization) achieved significant effects on physical activity. Twenty-four randomized studies of CVD secondary prevention were identified; 13 achieved significant effects on activity and/or fitness at twelve or more months. Studies with measurement at two time points showed decaying effects over time, particularly if the intervention were discontinued. Successful interventions contained multiple contacts, behavioral approaches, supervised exercise, provision of equipment, and/or continuing intervention. Many studies had methodologic problems such as low follow-up rates.Conclusion: Interventions in health care settings can increase physical activity for both primary and secondary prevention. Long-term effects are more likely with continuing intervention and multiple intervention components such as supervised exercise, provision of equipment, and behavioral approaches. Recommendations for additional research are given.     

Objectively measured physical activity,cardiorespiratory fitness and cardiometabolic risk factors in the Health Survey for England

Objectives

The study aims to test the hypothesis that physical activity (PA) and cardiorespiratory fitness (CRF) are associated with cardiometabolic risk factors; and to test the hypothesis that CRF modifies (changes the direction and/or strength of) the associations between PA and cardiometabolic risk factors.

Methods

PA and CRF were objectively measured in the 2008 Health Survey for England and the present study included 536 adults who completed at least 4 min of the eight-minute sub-maximal step test and wore an accelerometer for at least 10 h on at least four days. Linear regression models were fitted to examine the relationship between PA and cardiometabolic risk factors and between CRF and cardiometabolic risk factors. A test of interaction was performed to examine whether CRF modifies the associations between PA and cardiometabolic risk factors.

Results

PA and CRF were associated with HDL cholesterol, the ratio of total to HDL cholesterol, glycated haemoglobin and BMI after adjustment for potential confounders. There was little evidence that CRF changed the direction or strength of associations between PA and cardiometabolic risk factors.

Conclusions

PA and CRF are associated with cardiometabolic risk factors. A larger sample is required to determine if CRF modifies associations between PA and cardiometabolic risk factors.     

Physical activity, cardiorespiratory fitness, and obesity among Chinese children

Objective

To investigate the relationships of cardiorespiratory fitness (CRF) and physical activity (PA) with the risk of overweight/obesity in Chinese schoolchildren.

Methods

A total of 1795 children aged 8-13 years at baseline were followed-up for 18 months from 2006 to 2008 in Guangzhou, China. Children were categorized as “normal weight”, “overweight”, and “obese” using Chinese obesity cut-off points. Data on self-reported PA were obtained. CRF was determined by the 20-meter multistage fitness test, and the sex-specific median values were set as the cut-off points for the classification of high and low CRF.

Results

Significantly higher CRF was found in children with normal weight (from 6.55 to 8.65 ml/kg/min) or physically active children (from 0.42 to 1.22 ml/kg/min) compared with the reference group. CRF was inversely associated with the kg/m² change in BMI during the follow-up period (β = − 0.63 kg/m² and − 0.64 kg/m² for boys and girls, respectively, both p < 0.001). Significant association of baseline CRF with overweight/obesity was found in boys (odds ratio (OR) 8.71; 95% confidence interval (CI) 2.59-29.26, p < 0.001), whereas the association was marginally insignificant in girls (OR 6.87; 95% CI 0.96-49.09, p = 0.055).

Conclusions

The results showed a strong negative association between CRF levels and children's BMI and weight gain.     

Physical activity, metabolic syndrome, and overweight in rural youth.

BACKGROUND: Research suggests significant health differences between rural dwelling youth and their urban counterparts with relation to cardiovascular risk factors. This study was conducted to (1) determine relationships between physical activity and markers of metabolic syndrome, and (2) to explore factors relating to physical activity in a diverse sample of rural youth. METHODS: Data were collected from 4th, 6th, 8th, and 11th grade public school students in the rural Southeastern United States in the spring of 2002. Physiological data included anthropometrics, fasting glucose, lipids, hemodynamics, and skinfold measurements. Psychosocial data included parental support for physical activity, accessibility of physical activity facilities, and safety concerns for physical activity. Behavioral data included self-reported physical activity and sedentary behaviors. RESULTS: After adjusting for sex, race, and age, subjects with low level of physical activity were 3 times more likely to be positive for metabolic syndrome compared to those reporting a high level of physical activity. Subjects reporting a low level of physical activity were 2.4 times more likely to be overweight compared to subjects reporting a high level of physical activity. Students with high levels of physical activity were more likely to have parents who provided money for physical activity lessons and sports teams. CONCLUSIONS: Rural youth with low levels of physical activity participation were at increased risks for metabolic syndrome and overweight. Effective physical activity promotions addressing supports for physical activity are urgently needed in rural America.     

Central and total adiposity are lower in overweight and obese children with high cardiorespiratory fitness

OBJECTIVE: To examine the influence of cardiorespiratory fitness on total and truncal fatness in children. It was hypothesised that high cardiorespiratory fitness would result in lower total and central obesity. DESIGN: Observational cohort study. SETTING: Primary and secondary schools in Athens, Greece. SUBJECTS: A total of 1362 healthy children aged 6-13 y (742 boys and 620 girls). METHODS: Anthropometric data (height, body mass, four skinfolds thickness) were collected and per cent body fat was calculated. Body mass index (BMI) sex- and age-specific cutoff points were used for overweight and obesity definition and children were placed in two groups: overweight/obese and nonoverweight. Cardiorespiratory fitness (CRF) was assessed with the endurance shuttle-run test. Participants were grouped into high (upper two quintiles) and low (lower two quintiles) CRF based on age and sex distributions. T-test and Mann-Whitney test were used for comparisons between fit and unfit children within each BMI category. RESULTS: Sum of skinfolds, subscapular and truncal skinfold thickness, BMI and per cent body fat were lower in overweight and obese youths with high CRF in comparison with youths at the same BMI category with low CRF (P<0.01). The beneficial effect of high CRF was also presented in nonoverweight children (P<0.01). The influence of CRF on body composition remained even after correcting body fatness for BMI. CONCLUSIONS: Central and total obesity were lower in overweight and obese children with high CRF. This is the first study to show that a high CRF may reduce the hazards of obesity in children.     

Screen time and passive school travel as independent predictors of cardiorespiratory fitness in youth

Objective

The most prevalent sedentary behaviours in children and adolescents are engagement with small screen media (screen-time) and passive travel (by motorised vehicle). The objective of this research was to assess the independence of these behaviours from one another and from physical activity as predictors of cardiorespiratory fitness in youth.

Methods

We measured cardiorespiratory fitness in n = 6819 10-16 year olds (53% male) who self-reported their physical activity (7-day recall) school travel and screen time habits. Travel was classified as active (walking, cycling) or passive; screen time as < 2 h, 2-4 h or > 4 h.

Results

The multivariate odds of being fit were higher in active travel (Boys: OR 1.32, 95% CI: 1.09-1.59; Girls: OR 1.46, 1.15-1.84) than in passive travel groups. Boys reporting low screen time were more likely to be fit than those reporting > 4 h (OR 2.11, 95% CI: 1.68-2.63) as were girls (OR 1.66, 95% CI: 1.24-2.20). These odds remained significant after additionally controlling for physical activity.

Conclusion

Passive travel and high screen time are independently associated with poor cardiorespiratory fitness in youth, and this relationship is independent of physical activity levels. A lifestyle involving high screen time and habitual passive school travel appears incompatible with healthful levels of cardiorespiratory fitness in youth.     

Physical activity, cardiorespiratory fitness, and adiposity: contributions to disease risk

PURPOSE OF REVIEW: To discuss assessing physical activity, cardiorespiratory fitness, and adiposity in the context of examining their prospective joint associations with mortality in cohort studies. RECENT FINDINGS: Accurate and comprehensive assessment of free-living physical activity patterns and related energy expenditure is difficult. Cardiorespiratory fitness is a reproducible measure associated with recent physical activity patterns; however, its assessment has been considered impractical in epidemiologic studies. Likewise, objective measures of adiposity and fat distribution often are not feasible in large studies. Thus, physical activity and adiposity exposures typically are quantified using self-reports of physical activity habits and of height and weight to compute body mass index. When considered jointly, adults with higher levels of fitness or reported physical activity tend to have lower mortality risk than their unfit and inactive peers within the same body mass index group. SUMMARY: Accumulating evidence suggests that higher physical activity or fitness attenuates the health risks of obesity. Available data largely are based on crude measures of physical activity and body habitus, which may obscure their association with disease risk. Accurate measures must be included in epidemiologic studies to improve estimation of the independent and joint associations of these exposures with health outcomes.     

Acculturation,physical activity,and obesity among Hispanic adolescents

Objective. Little is known about how acculturation may influence participation in leisure-time physical activity and obesity among adolescents. The objective of this study was to examine these associations among Hispanic adolescents.

Design. Data were drawn from the 2003 National Survey of Children's Health, restricted to Hispanic adolescents aged 10–17 (n=4704). Acculturation was assessed by proxy measures (generation status and language spoken at home). Adolescents who were not reported to engage in physical activity lasting at least 20 minutes, that was vigorous enough to cause sweating and hard breathing, for at least three days per week were defined as failing to meet physical activity requirements. Obesity was defined as gender and age-specific body mass index values at or above the 95th percentile of the reference population. Multiple logistic regressions were performed to adjust for confounders.

Results. Of the Hispanic adolescents studied, 25.2%, 43.8%, and 31.1% were first, second, and third generation or more, respectively. English was the primary language in the home for 42.8% of these adolescents. Compared with adolescents in the third generation, adolescents from immigrant families had higher odds for not obtaining recommended physical activity (first generation: adjusted odds ratio [AOR] = 1.50, 95% conference intervals [CI]: 1.09, 2.05; second generation: AOR = 1.29, 95% CI: 0.99, 1.69). Living in homes where English was not the primary language, vs. English-speaking homes, was also associated with not obtaining recommended physical activity (AOR = 1.36, 95% CI: 1.06, 1.75). The unadjusted prevalence of obesity was higher in homes where English was not the primary language (22.5% vs. 16.1%; p<0.01), but this difference disappeared after adjusting for family socioeconomic status. Generational status was not a significant correlate of obesity.

Conclusions. Findings suggest that future public health interventions that aim to increasing physical activity among Hispanic adolescents should be tailored based on generational status and English-language use.     

Systematic review of the health benefits of physical activity and fitness in school-aged children and youth

Background  

The purpose was to: 1) perform a systematic review of studies examining the relation between physical activity, fitness, and health in school-aged children and youth, and 2) make recommendations based on the findings.