Change In Vigorous Physical Activity Research Articles

Physical activity, ethnicity, and quality of life among breast cancer survivors and population-based controls: the long-term quality of life follow-up study.

To explore the relationship between physical activity (PA) and quality of life (QOL) among Hispanic and non-Hispanic white breast cancer (BC) cases and population-based controls from the New Mexico 'Long-Term Quality of Life Study'. Self-reported PA (low, moderate, vigorous MET hours/week) at baseline and follow-up interviews (12-15years) were available for 391 cases and controls and modeled using multiple linear regressions with SF-36 mean composite scores for physical and mental health. The change in PA from baseline to follow-up and interactions with ethnicity were also examined. Models were adjusted for age at diagnosis/baseline interview, education, comorbidities, body mass index, and change in PA. PA intensities at each timepoint did not differ by case/control status; however, the change in vigorous PA was lower among cases (p = 0.03). At follow-up, low intensity PA increased mental health QOL scores among cases; however, the interaction between low intensity PA and ethnicity was statistically significant among controls indicating decreased mental health among Hispanics (p = 0.02). Change in moderate PA was associated with increased physical and mental health among cases (physical: β = 0.186, p = 0.008; mental: β = 0.225, p = 0.001) and controls (physical: β = 0.220, p < 0.0001; mental: β = 0.193, p = 0.002), when controlling for confounders. Our results demonstrate that all levels of PA are important for mental health among BC cases, while activities of higher intensity are important for physical health among women overall. The statistical interaction observed between ethnicity and low intensity PA among controls for mental health warrants further research to provide a meaningful interpretation.

Institutional factors associated with college students’ healthy physical activity and body composition: A first semester follow-up

Objective The first aim of this study was to examine changes in freshman college students’ health-enhancing physical activity (PA) and body composition across the first semester. Secondly, this study aimed to explore the role of socio-ecological variables on these processes. Methods: A sample of 166 participants (108 females, 58 males, Mage = 18.14[.96]) completed self-report pre-and posttest data on vigorous PA (VPA), moderate-to-vigorous PA (MVPA), and body mass index (BMI). Results: The results showed a statistically significant increase in BMI, but no statistically significant changes in VPA or MVPA. The findings revealed that our socio-ecological model predicted .71, .39, and .92 percent of the end of the year VPA, MVPA, and BMI, respectively. The findings highlighted the positive role of peer support, positive motivation, and university’s Recreational Services on measured healthy behaviors. Conclusions: These findings suggest a need to increase college students’ VPA.

The Impact of COVID-19 Lockdown on Health Behaviors among Students of a French University.

This study aimed to determine the changes in health behaviors among students of a French university during the COVID-19 lockdown. An online retrospective survey was distributed to Rouen-Normandy University students at the end of the COVID-19 lockdown (13th March–11th May 2020). Voluntary university students were included. Data collected were on socio-demographics, academic environment, COVID19 concerns, tobacco smoking, binge drinking, cannabis use, and physical activity in the periods before and during COVID-19 lockdown. The survey was completed by 3671 university students (mean age 20.9 ± 2.47 years, 72.9% female). Significantly favorable changes between the periods before and during COVID-19 were reported for tobacco smoking (18.5% vs. 14.8%), binge drinking (35.9% vs. 9.3%) and cannabis use (5.6% vs. 3.2%) and unfavorable changes for moderate (79.4% vs. 67.9%) and vigorous physical activity (62.5% vs. 59.1%). After logistic regression, factors associated with unfavorable changes in tobacco smoking and with favorable changes in vigorous physical activity were the worry of not validating the academic year and stress related to changes in the mode of teaching, respectively. For each health behavior, unfavorable changes were associated with higher depression levels, and male gender. Then as a decrease, mainly in binge drinking was observed during the COVID-19 lockdown, care must be taken to prevent university students from resuming binge drinking after the end of the lockdown. Health-promotion strategies directed at adopting or maintaining positive mental health and promoting physical activity should be developed for university students to better manage future lockdown periods.

Longitudinal associations of physical activity, sedentary time, and cardiorespiratory fitness with arterial health in children – the PANIC study

ABSTRACT We investigated the longitudinal associations of physical activity (PA), sedentary time (ST), and cardiorespiratory fitness (CRF) with arterial health among children. In our primary analyses, we investigated 245 children (girls 51.8%) aged 6-9 years participating in the baseline examinations who had data on arterial health at 2-year follow-up. We also utilized a subsample of 90 children who had a complete arterial health data at baseline and 2-year follow-up. ST (≤1.5 METs), light PA (>1.5-4 METs), moderate PA (>4-7 METs), vigorous PA (>7METs), and moderate-to-vigorous PA (MVPA, >4 METs) were assessed by combined movement and heart rate monitoring and CRF by maximal exercise testing on a cycle ergometer at baseline and 2-year follow-up. Stiffness index (SI) as a measure of arterial stiffness and change in reflection index during exercise test (DRI) as a measure of arterial dilation capacity were assessed by pulse contour analysis. Two-year change in vigorous PA was associated with DRI in boys but not in girls (p=0.021 for interaction). In a subsample analyses, 2-year changes in MPA, VPA, and MVPA were inversely associated with 2-year change in SI. In conclusion, promoting PA at higher intensities may confer larger benefits on arterial health than reducing ST and increasing LPA.

Impact of a group-based intervention program on physical activity and health-related outcomes in worksite settings

BackgroundThe benefits of physical activity (PA) have been well documented, and the worksite is a promising setting for PA promotion. The aims of this study were as follows: 1. To evaluate the effect of a group-based worksite intervention on PA and health-related outcomes by using pedometers. 2. To examine the associations between the change in vigorous physical activity (VPA)/moderate physical activity (MPA)/walking and health related outcomes.MethodsA total of 398 participants (221 in the intervention group (IG) and 177 in the control group (CG)) from 17 worksites were recruited for a prospective self-controlled trial of a worksite physical activity intervention program in China. In the IG, a pedometer was utilized to self-monitor the PA, together with group competition, goal setting, and other incentives. No intervention was applied to the CG. Physical activity, sedentary behavior, and health-related outcomes were measured at baseline and immediately after the 100-day period intervention.ResultsA total of 262 participants completed the program (68.3% adherence). Adherence in the intervention group was 67.9% (n = 150/221). Improvements between baseline and follow-up among intervention participants were observed in the following parameters: VPA (+ 109.7 METs/week; p < 0.05), walking (+ 209.2 METs/week; p < 0.01), systolic blood pressure (SBP; − 2.1 mmHg; p < 0.01), waist circumference (WC; − 2.3 cm; p < 0.01), body fat percentage (BF); − 1.0%; p < 0.01), and body mass index (BMI; − 0.5 kg/m2; p < 0.01). VPA was related to changes in body fat percentage (p < 0.05) and body mass index (p < 0.05).ConclusionThis integrated group-based intervention program contributed to comprehensive improvement in health-related outcomes. The study was useful for establishing associations between change in VPA/MPA/walking and health-related outcomes in a natural setting. Long-term evaluation is required to examine the potential of such an integrated intervention to promote PA.RegistrationThis study was prospectively registered in the Chinese Clinical Trial Registry. Trial registration number: ChiCTR-1,800,015,529. Date of registration: April 5, 2018.

Changes in Physical Performance During 21 d of Military Field Training in Warfighters.

Few studies have reported the amount of physical activity (PA) and its associations to physical performance of warfighters during military field training (MFT). The purpose of this study was to investigate changes in neuromuscular performance and PA among male Finnish Army conscripts during a 21-d MFT and to evaluate their recovery during 4 d after MFT. Body composition and physical performance were measured four times during the study (before MFT (PRE), after 12 d (MID), post training (POST) and after 4 d of recovery (RECO)). PA was measured throughout MFT in a group of healthy young male conscripts (n=49) by using a tri-axial accelerometer. The study was approved by the Finnish Defence Forces and was granted ethics approval by the Ethics Committee of the University of Jyväskylä. Body mass declined significantly from 73.5 ± 8.7 to 71.6 ± 8.2 kg, but it recovered close to the PRE values (73.0 ± 8.3 kg). The same trend was also found in skeletal muscle mass and fat mass. The change in body mass and in skeletal muscle mass correlated negatively with the change in vigorous physical activity (r = -0.374, p = 0.016, and r = -0.337, p = 0.031, respectively). Muscular endurance decreased significantly (p < 0.001) in sit-ups from the PRE (46 ± 9 reps/min) values compared with MID (40 ± 8 reps/min), POST (42 ± 8 reps/min), and RECO (34 ± 11 reps/min) values. Also in push-ups, the declines in the POST (34 ± 10 reps/min) and RECO (34 ± 13 reps/min) values (p < 0.001) from the PRE (40 ± 13 reps/min) and MID (39 ± 12 reps/min) values were observed. There was a significant decrease in a standing long jump in all measurement points MID (220 ± 20 cm), POST (216 ± 20 cm), and RECO (213 ± 20 cm) as compared with the PRE values (229 ± 23 cm, p < 0.001). There was no change in 3.2 km loaded march time between the PRE (23:57 ± 4:12 min:s) and POST (23:44 ± 5:02 min:s) measurement time points. In PA, the total number of steps per day was significantly (p < 0.001) greater during ST (13,722 ± 2,379 steps) and MFT (13,937 ± 2,276 steps) than during garrison days (9,550 ± 2,569 steps). In POST, there was significantly (p < 0.001) more light (1.5-3.0 metabolic equivalent) (2:34:38 ± 0:22:53 h:min:s in ST and 3:03:27 ± 0:23:24 h:min:s in MFT) and moderate (3.0-6.0 metabolic equivalent) (2:12:15 ± 0:23:14 h:min:s in ST and 2:47:59 ± 0:27:23 h:min:s in MFT) PA than in the PRE measurements. This study demonstrated slight decrements in warfighter physical performance during the 21-d MFT. The conscripts were overloaded during MFT, but 4 d of recovery seemed not to be enough to obtain the PRE measurement values in physical performance. This study also showed changes in the muscular endurance levels and PA during the 21-d MFT. It is important for warfighters to have a good physical fitness level PRE training or combat. As the prolonged MFT may have adverse effects in warfighters muscular endurance and PA levels, it is important to have sufficient recovery time after long MFT to regain combat readiness.

Exploring The Link Between Exercise Identity And Intervention Dosage

Adolescent overweight and obesity in the United States has increased in past decades, resulting in numerous physiological and psychological consequences. Obesity interventions often aim to increase physical activity (PA). Such interventions may strengthen Exercise Identity (EI). A strong EI has been positively related to long-term PA engagement, as individuals seek to engage in behaviors congruent with the role identity of “exerciser.” Greater dosage of PA intervention may progressively increase EI, and enhance future exercise behavior. However, the relationship between PA intervention dosage and EI in an overweight and obese adolescent population is unclear. PURPOSE: To determine if a PA intervention, when delivered in varying dosages, may strengthen an overweight or obese adolescent’s EI. METHODS: Fifty overweight and obese adolescents (age=14.16 ± 1.88 years, BMI=35.66 ± 7.87 kg/m2, BMI percentile=97.5% ± 3.7%) were recruited from a behavior change summer camp, which included a PA intervention component. Age, gender, height, and weight were collected, and BMI was calculated. The participants were categorized into three separate groups, according to length of PA intervention (dosage): 3 week PA dosage, 4-5 week PA dosage, and 6-7 week PA dosage. Participants completed the Anderson Exercise Identity Scale and 3 Day Physical Activity Recall (3DPAR) at pre- and post-intervention. Group comparisons of EI were made using two-way ANOVA. Changes in vigorous physical activity (VPA) within groups were calculated using Log-Rank, Kaplan-Meier, and Wilcoxon. Activities on the 3DPAR were categorized and coded to compare exercise behavior within groups. RESULTS: Upon comparison, the mean EI in the 6-7 week intervention group significantly differed from other group means and resulted in a significant increase in EI within groups (p<0.001). All intervention groups demonstrated significant increases in VPA (p<0.05), and complied with National PA Guidelines of 60+ minutes of MVPA daily; VPA performed on at least 3 days/week. CONCLUSION: Exercise Identity may be increased in overweight and obese adolescents following a physical activity intervention. Greater dosage of physical activity intervention will result in greater benefits to Exercise Identity, and may ultimately enhance long-term exercise behavior.

Abstract MP026: Effects of Substituting Sedentary Behavior With Light and Moderate-to-vigorous Physical Activity on Obesity Indices in Adults

Sedentary behavior (SB) has emerged as an independent risk factor for the occurrence of cardiovascular problems and all-cause mortality. However, the deleterious effect of SB may be a consequence of replacing time spent in light and moderate-to-vigorous (MVPA) physical activities. Few studies have explored this topic, especially in prospective follow-up studies with adults. We hypothesized that substituting SB with light and MVPA may be associated with 1-year change in body weight, body mass index (BMI) and fat body mass (FBM) in asymptomatic adults. We aimed to use isotemporal substitution modeling to investigate cross-sectional and longitudinal effects of reallocating SB with light and MVPA on obesity indices in asymptomatic adults. Also, we examined the correlations between 1-year changes in physical activity intensity categories (i.e., sedentary, light, moderate, vigorous, very vigorous, and MVPA) and changes in FBM. We included 780 participants over the age of 20-yr. Body weight, BMI, and FBM (bioelectrical impedance), as well as its 1-year changes, were the outcomes. We objectively measured physical activity using triaxial accelerometers (ActiGraph GT3X) worn above the dominant hip during waking hours for at least four consecutive days (4-7 days). After 1-year follow-up, 242 completed all the assessments. We reallocated time spent in SB by light or MVPA and assessed the cross-sectional and prospective associations with the outcomes. The cross-sectional isotemporal substitution analysis showed that substituting 10-min blocks of SB with MVPA was significantly related to decreases of 1.23 kg in body weight, 0.30 kg/m2 in BMI and 0.38% in FBM. Substituting 10-min blocks of SB with light physical activity produced significant lower values of body weight (1 kg) and BMI (0.1 kg/m2). We found no effects of substituting SB with light physical activity on FBM. As for the longitudinal analysis, we observed that reallocating SB with MVPA was only associated with a significant decline in FBM (-0.31%). We found no other significant effects of substituting SB with light or MVPA. We observed significant correlations between change in FBM and changes in sedentary (r = 0.147), light (r = -0.290) and vigorous (r = -0.277) physical activity. After stepwise multiple regressions adjusted for all physical activity intensities and covariates, change in vigorous physical activity was the only intensity selected as a significant predictor for 1-year absolute change in FBM (β = -0.312; ΔR 2 = 0.102). We may conclude that SB presents non-consistent influence on obesity indices in asymptomatic adults and its substitution with MVPA is associated with significant improvement in body composition over a short-term follow-up. Our results suggest that vigorous physical activities play the most important role in obesity in adults.

Effectiveness of a Worksite Intervention for Male Construction Workers on Dietary and Physical Activity Behaviors, Body Mass Index, and Health Outcomes: Results of a Randomized Controlled Trial.

To evaluate the effectiveness of an individually tailored intervention for improvement in lifestyle behavior, health indicators, and prevention and reduction of overweight among construction workers. Randomized controlled trial. Various blue-collar departments of a large construction company in the Netherlands. Blue-collar workers randomized to an intervention (n = 162) or a control group (n = 152). The intervention group received individual coaching sessions, tailored information, and materials to improve lifestyle behavior during a 6-month period, and the control group received usual care. Body weight, body mass index (BMI), waist circumference, physical activity (PA) levels, dietary behavior, blood pressure, and blood cholesterol were assessed. Effectiveness of the intervention on outcome measures at 6- and 12-month follow-up was assessed by using linear and logistic regression models adjusting for baseline levels. After 6 months, a statistically significant intervention effect was found on body weight ( B = -1.06, P = .010), BMI ( B = -0.32, P = .010), and waist circumference ( B = -1.38, P = .032). At 6 months, the percentage of those meeting public health guidelines for PA increased significantly in the intervention group compared to the control group ( B = 2.06, P = .032), and for sugar-sweetened beverages, an intervention effect was found at 6 months as well ( B = -2.82, P = .003). At 12 months, for weight-related outcomes, these differences were slightly smaller and no longer statistically significant. The intervention was not effective on the total amount of moderate to vigorous PA and other dietary and health outcomes. Intervention participants showed positive changes in vigorous PA and intake of sugar-sweetened beverages compared to controls, as well as effects on weight-related outcomes at 6 months. Long-term effects were still promising but not statistically significant.

The Association of Physical Activity during Weekdays and Weekend with Body Composition in Young Adults.

Physical activity (PA) is a key contributor in long-term weight management but there remains limited research on the association between weekly PA patterns and weight change. The purpose of the present study was to examine the prospective association between weekly PA patterns and weight change in generally healthy young adults. Anthropometric measurements, including dual X-ray absorptiometry, were obtained every 3 months over a period of one year in 338 adults (53% male). At each measurement time, participants wore a multisensor device for a minimum of 10 days to determine total daily energy expenditure and time spent sleeping, sedentary, in light PA (LPA), in moderate PA (MPA), and in vigorous PA (VPA). PA did not differ between weekdays and the weekend at baseline. Twenty-four-hour sleep time, however, was significantly longer during weekends compared to weekdays, which was associated with less time spent sedentary. Weight loss was associated with a significant increase in LPA at the expense of sedentary time during the weekend but not during weekdays. Regression analyses further revealed an inverse association between change in VPA during the weekend and body composition at 12-month follow-up. Taken together, these results suggest that weekend PA plays an important role in long-term weight management.

A Web-Based, Social Networking Physical Activity Intervention for Insufficiently Active Adults Delivered via Facebook App: Randomized Controlled Trial.

BackgroundOnline social networks offer considerable potential for delivery of socially influential health behavior change interventions.ObjectiveTo determine the efficacy, engagement, and feasibility of an online social networking physical activity intervention with pedometers delivered via Facebook app.MethodsA total of 110 adults with a mean age of 35.6 years (SD 12.4) were recruited online in teams of 3 to 8 friends. Teams were randomly allocated to receive access to a 50-day online social networking physical activity intervention which included self-monitoring, social elements, and pedometers (“Active Team” Facebook app; n=51 individuals, 12 teams) or a wait-listed control condition (n=59 individuals, 13 teams). Assessments were undertaken online at baseline, 8 weeks, and 20 weeks. The primary outcome measure was self-reported weekly moderate-to-vigorous physical activity (MVPA). Secondary outcomes were weekly walking, vigorous physical activity time, moderate physical activity time, overall quality of life, and mental health quality of life. Analyses were undertaken using random-effects mixed modeling, accounting for potential clustering at the team level. Usage statistics were reported descriptively to determine engagement and feasibility.ResultsAt the 8-week follow-up, the intervention participants had significantly increased their total weekly MVPA by 135 minutes relative to the control group (P=.03), due primarily to increases in walking time (155 min/week increase relative to controls, P<.001). However, statistical differences between groups for total weekly MVPA and walking time were lost at the 20-week follow-up. There were no significant changes in vigorous physical activity, nor overall quality of life or mental health quality of life at either time point. High levels of engagement with the intervention, and particularly the self-monitoring features, were observed.ConclusionsAn online, social networking physical activity intervention with pedometers can produce sizable short-term physical activity changes. Future work is needed to determine how to maintain behavior change in the longer term, how to reach at-need populations, and how to disseminate such interventions on a mass scale.Trial RegistrationAustralian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12614000488606; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=366239 (Archived by WebCite at http://www.webcitation.org/6ZVtu6TMz).

Adherence, Compliance, and Health Risk Factor Changes following Short-Term Physical Activity Interventions.

Background. Low physical activity (PA) levels are associated with poor health risk factor profiles. Intervention strategies to increase PA and quantify the rate and magnitude of change in risk factors are important. Methods. Interventions were conducted over 40 days to increase PA in 736 insufficiently active (<150 min/wk PA) participants using either a pedometer or instructor-led group protocol. There were a further 135 active participants as controls. Major cardiovascular and metabolic risk factors, including fitness parameters, were measured before and after intervention. Results. Adherence to the interventions was higher for the group versus pedometer participants (87.1% versus 79.8%) and compliance rates for achieving sufficient levels of PA (≥150 min/wk) were also higher for the group participants (95.8% versus 77.6%). Total weekly PA patterns increased by 300 and 435 minutes, for the pedometer and group participants, respectively. Improvements were found for waist girth, total cholesterol, aerobic fitness, and flexibility relative to controls. The change in vigorous PA, but not moderate PA, was a significant predictor of the change in eight of 11 risk factor variables measured. Conclusions. Rapid and dramatic increases in PA among previously insufficiently active adults can result in important health benefits.

Abstract MP83: Increases in Vigorous Physical Activity Improve Pulse Wave Velocity in Adolescents

Introduction: The beneficial effects of vigorous physical activity (VPA) on arterial stiffness have been established, but the effect of changes in VPA over time on these vascular measures is unclear. Hypothesis: Increases in VPA will be associated with improvement in measures of arterial stiffness. Methods: As part of a longitudinal study of the effects of obesity &amp; diabetes on cardiovascular health, 317 subjects (mean age 17.2 years at baseline, 38% male, 63% non-Caucasian) were enrolled and followed up 5 years later. Anthropometrics, accelerometer-measured physical activity, blood pressure, central and peripheral measures of arterial stiffness (pulse wave velocity (PWV), brachial distensibility (BrachD), and augmentation index (AI)), and blood (lipids &amp; metabolic tests) were collected. General linear modeling was performed to test for the independent relationship of change in VPA with change of arterial stiffness. Results: Overall, VPA increased slightly (0.2 minutes) from baseline to follow up. Increased VPA from baseline to follow up was significantly associated (P = 0.0364) with a decrease in PWV but was not associated with a change in BrachD nor AI. The effect of change in VPA on change in PWV was independent of change in glucose (P = 0.024), but not independent of changes in BMI, blood pressure, lipids, or CRP. Conclusions: Increase in vigorous physical activity during late adolescence is significantly associated with improved pulse wave velocity. This relationship may be mediated through improvements in other cardiovascular risk factors such as body mass index, blood pressure, and lipids.

The effectiveness of a motivational interviewing primary-care based intervention on physical activity and predictors of change in a disadvantaged community

Little research exists on the impact of behavior change interventions in disadvantaged communities. We conducted a prospective study to explore the effectiveness of motivational interviewing on physical activity change within a deprived community and the social- psychological and motivational predictors of change in physical activity including stage of change, self-efficacy, social support, and variables from self-determination theory and the theory of planned behavior. Five motivational interviewing counsellors recruited 207 patients and offered motivational interviewing sessions to support physical activity behavior change. At 6-months there were significant improvements in physical activity, stage of change, and social support. A dose-response relationship was evident; those who attended 2 or more consultations increased their total physical activity, stage of change and family social support more than those who attended just one. Hierarchical regression analyses indicated that number of sessions and change in stage of change predicted 28.4% of the variance in change in total physical activity and, with social support from friends, 21.0% of the variance in change walking time. Change in perceived behavioral control and attitudes, friend social support, and number of sessions predicted 16.8% of the variance in change in vigorous physical activity. Motivational interviewing is an effective approach for promoting physical activity amongst lower socio-economic status groups in the short term. The study demonstrates good translational efficacy, and contributes to a limited number of physical activity interventions targeting low income groups in the UK.

Impact Evaluation of a Pilot Web-Based Intervention to Increase Physical Activity

The purpose of this pilot study was to conduct an impact evaluation of a 10-week Web-based physical activity intervention. Quasi-experimental, three-group pretest, posttest design. Large Midwestern university. Participants (N = 233) included college students registered for three courses. The study employed a convenience sample consisting of a Web-based group (n = 108), a physical activity group (n = 64), and a general health group (n = 61). The Web-based group received a Social Cognitive Theory behavioral skill-building intervention and exercised 3 days per week in their leisure time. The physical activity group received exercise instruction and was required to attend three physical activity labs per week. The comparison group received health instruction. Outcome variables included moderate and vigorous physical activity, self-regulation, social support, self-efficacy, and outcome expectations and expectancies. Differences between groups were assessed at pretest and posttest using multiple analyses of variance. Vigorous physical activity, self-regulation, and outcome expectancy value changed significantly in the Web-based and physical activity course groups (p < .01). Even with consideration of limitations such as small sample size and lack of randomization, the Web-based and traditional physical activity lecture and activity lab interventions were superior in eliciting changes in vigorous physical activity, self-regulation, and outcome expectancy value than a traditional health course.

Do intervention fidelity and dose influence outcomes? Results from the Move to Improve worksite physical activity program

The purpose of this paper is to evaluate the implementation of the Move to Improve worksite physical activity program using a four step framework that includes the following: (i) defining the active ingredients, (ii) using good methods to measure implementation, (iii) monitoring implementation and (iv) relating implementation to outcomes. The intervention active ingredients consisted of a goal setting behavior change program, a team competition and environmental supports. Intervention fidelity and dose were measured by surveys administered to site co-ordinators, team captains and employees. Implementation was monitored by the use of biweekly assessments that tracked individual physical activity levels and through weekly reports of the project director and site co-ordinators. Latent growth modeling was conducted to determine whether intervention outcomes were affected by site implementation (i.e. fidelity) and/or participation by employees (i.e. dose). Results showed high levels of intervention fidelity, moderate to high levels of intervention dose delivered and moderate levels of the intervention dose received. Level of implementation affected the degree of change in vigorous physical activity (Mean = 5.4 versus 2.2; chi(2) = 4.9, df = 1), otherwise outcome measures were unaffected by fidelity and dose. These findings suggest that practitioners should focus more energy assuring that the core components are fully implemented and be less concerned about the level of participation.

Incident Hypercholesterolemia in Relation to Changes in Vigorous Physical Activity

Test whether changes in vigorous exercise affect the risk for hypercholesterolemia. : Incident physician-diagnosed hypercholesterolemia was compared in recreational runners whose weekly distances run increased >0.5 km x d (4034 men, 1897 women), remained constant (+/-0.5 km x d; 4685 men, 1904 women), or decreased >0.5 km x d (15,678 men, 6224 women) during 7.8 yr of prospective follow-up. Relative to those whose distance was maintained or reduced, the odds ratio (95% confidence interval) for hypercholesterolemia for those whose running increased was significantly less than 1 for men {0.82 (0.72-0.93), P = 0.0006}, women {0.71 (0.54-0.92), P = 0.01}, and men and women combined adjusted for sex {0.80 (0.72-0.89), P < 0.0001}. The significance of the odds ratios was somewhat diminished when adjusted for baseline and follow-up BMI in men {0.89 (0.79-1.01), P = 0.06}, women {0.71 (0.54-0.92), P = 0.08}, and the adjusted sexes combined {0.88 (0.79-0.98), P = 0.02}. When average distance run {i.e., (baseline + follow-up) / 2} was compared with incident hypercholesterolemia in the 6589 runners whose distance remained constant, each kilometer-per-day increment in average running distance was associated with an odds ratio significantly less than 1 in men {0.90 (0.86-0.93)}, women {0.91 (0.84-0.98)}, and the adjusted sexes combined {0.90 (0.87-0.93)}, which was also attributable in part to BMI in men {0.94 (0.90-0.97), P = 0.0005}, women {0.96 (0.89-1.04), P = 0.35}, and the adjusted sexes combined {0.94 (0.91-0.97), P = 0.0003}. The odds for hypercholesterolemia 1) decrease in runners who increase their running mileage and 2) decline in association with the higher dose of vigorous activity even in the absence of any change in exercise. These effects are associated in part to the runners' BMI.

A cohort study of incident hypertension in relation to changes in vigorous physical activity in men and women.

To assess the dose-response relationship between changes in vigorous exercise (running distance, Deltakm per week) and physician-diagnosed hypertension. Twenty-four thousand, five hundred and fifty men and 10 113 women were followed prospectively for (mean +/- SD) 7.8 +/- 1.8 and 7.5 +/- 2.0 years, respectively. Among those who maintained their running distance within +/-5 km per week (5841 men), logistic regression showed that the log odds for hypertension was significantly lower for those who ran longer distances (coefficient+/-SE:-0.019 +/- 0.003 per km per week; P < 0.0001) even when adjusted for body mass index (-0.010 +/- 0.003 per km per week; P = 0.002). Analyses of all 24 550 male and 10,113 female runners showed that the log odds for hypertension declined significantly in relation to Deltakm per week in men (-0.009 +/- 0.001; P < 0.0001) and women (-0.006 +/- 0.003; P = 0.03), which remained significant when adjusted for body mass index in men (-0.005 +/- 0.001; P < 0.0001) but not in women (-0.004 +/- 0.003; P = 0.13). In both sexes, the decline was related to the distance run at the end of follow-up but not at baseline. Compared with men who ran less than 8 km per week, the age-specific rate for incident hypertension in those who ran more than 40 km per week at the end of follow-up was 80% lower in those aged between 35 and 44 years, 66% lower in those between 45 and 54 years, 69% lower in those aged between 55 and 64 years (all P < 0.0001), and 57% lower in those older than 65 years (P = 0.08). The odds of developing hypertension are reduced in those who remain vigorously active and increased in those whose vigorous activity declined. These effects are dependent on the exercise dose and are due in part to metabolic processes associated with body weight.

Vigorous Physical Activity Determines Magnitude of Cardiovascular Risk Factor Changes Following Physical Activity Interventions

Physical activity (PA) is a significant determinant of good health yet it continues to decline in most countries. Interventions promoting PA are therefore important public health initiatives. PURPOSE: To measure the impact of 40-days intensive PA on CV and metabolic risk factors, and to follow subjects for 6 months to document both PA patterns and risk factor changes. METHODS: Two 40-day programs were designed to increase PA among insufficiently active adults randomly assigned to a: (1) pedometer-based (n=251), or (2) group-based intervention arm (n=187). An active control group was also followed (n=135). The pedometer subjects were advised about the 10,000-step goal and provided diaries and pedometers. Group subjects used heart rate monitors to record all daily sessions. Half the sessions were led while the others were performed individually. Sessions gradually progressed to vigorous levels of activity. Health risk factors including fitness parameters were measured pre- and post-intervention, and at 3 and 6 months follow-up. RESULTS: Adherence rates at post intervention, 3 and 6 months were 84, 69 and 61% for pedometer and 86, 76 and 71% for group subjects. Significant improvements occurred in cholesterol, BMI, VO2max, waist girth, and total and vigorous PA measures during both 40-day intervention arms. Repeated measures ANOVA showed significant group × intervention interactions for all these variables (group > pedometer, p<0.01). Regression analysis showed changes for cholesterol and VO2max, between each test over the study period, were significantly related to the corresponding changes in vigorous PA but not moderate PA (p<0.0001). BMI changes were related to both. Repeated measures ANOVA (using intention to treat analysis) showed significant improvements remained at 6 months for VO2max, BMI, and both total and vigorous minutes of PA for both intervention arms. Improvements remained for cholesterol at 3 months. CONCLUSION: Significant changes in risk factor profiles were found in both interventions over the 40-day program and most improvements remained at 6 months. Vigorous PA was significantly associated with the magnitude of risk factor changes. Supported by the South Australian Department of Health and Australian Research Council.

Changes in Vigorous Physical Activity and Incident Diabetes in Male Runners

We examined the relationship between changes in reported vigorous exercise and self-reported physician-diagnosed diabetes in 25,988 active men. The dose-response relationship between changes in reported vigorous exercise (running distance, change in kilometers per week) and self-reported physician-diagnosed diabetes was followed prospectively for 7.8 +/- 1.8 years (means +/- SD). Logistic regression analyses showed that the log odds for diabetes declined significantly in relation to men's change in running distance (coefficient +/- SE: -0.012 +/- 0.004, P < 0.01), which remained significant when adjusted for BMI (-0.018 +/- 0.003, P < 0.0001). The decline in the log odds for diabetes was related to the distance run at the end of follow-up when adjusted for baseline distance, with (-0.024 +/- 0.005, P < 0.0001) or without (-0.027 +/- 0.005, P < 0.0001) adjustment for BMI. Baseline distance was unrelated to diabetes incidence when adjusted for the distance at the end of follow-up. Compared with men who ran < 8 km/week at the end of follow-up, incidence rates in those who ran > or = 8 km/week were 95% lower between 35 and 44 years of age (P < 0.0001), 92% lower between 45 and 54 (P < 0.0001), 87% lower between 55 and 64 (P < 0.0001), and 46% lower between 65 and 75 (P = 0.30). For the subset of 6,208 men who maintained the same running distance during follow-up (+/-5 km/week), the log odds for diabetes declined with weekly distance run (-0.024 +/- 0.010, P = 0.02) but not when adjusted for BMI (-0.005 +/- 0.010, P = 0.65). Vigorous exercise significantly reduces diabetes incidence, due in part to the prevention of age-related weight gain and in part to other exercise effects.