Brian W. Martin

Correlates of physical activity: why are some people physically active and others not?

Physical inactivity is an important contributor to non-communicable diseases in countries of high income, and increasingly so in those of low and middle income. Understanding why people are physically active or inactive contributes to evidence-based planning of public health interventions, because effective programmes will target factors known to cause inactivity. Research into correlates (factors associated with activity) or determinants (those with a causal relationship) has burgeoned in the past two decades, but has mostly focused on individual-level factors in high-income countries. It has shown that age, sex, health status, self-efficacy, and motivation are associated with physical activity. Ecological models take a broad view of health behaviour causation, with the social and physical environment included as contributors to physical inactivity, particularly those outside the health sector, such as urban planning, transportation systems, and parks and trails. New areas of determinants research have identified genetic factors contributing to the propensity to be physically active, and evolutionary factors and obesity that might predispose to inactivity, and have explored the longitudinal tracking of physical activity throughout life. An understanding of correlates and determinants, especially in countries of low and middle income, could reduce the eff ect of future epidemics of inactivity and contribute to effective global prevention of non-communicable diseases.

Effect of school-based interventions on physical activity and fitness in children and adolescents: a review of reviews and systematic update

Background School-based interventions are thought to be the most universally applicable and effective way to counteract low physical activity (PA) and fitness although there is controversy about the optimal strategy to intervene. Objectives The objective of this review was to summarise recent reviews that aimed to increase PA or fitness in youth and carry out a systematic review of new intervention studies. Methods Relevant systematic reviews and original controlled and randomised controlled school-based trials with a PA or fitness outcome measure, a duration of ≥12 weeks, a sufficient quality and involvement of a healthy population aged 6–18 years that were published from 2007 to 2010 were included. Results In these reviews, 47–65% of trials were found to be effective. The effect was mostly seen in school-related PA while effects outside school were often not observed or assessed. Conclusions The school-based application of multicomponent intervention strategies was the most consistent, promising strategy, while controversy existed regarding the effectiveness of family involvement, focus on healthy populations at increased risk or duration and intensity of the intervention. All 20 trials in the review update showed a positive effect on in-school, out-of-school or overall PA, and 6 of 11 studies showed an increase in fitness. Taking into consideration both assessment quality and public health relevance, multicomponent approaches in children including family components showed the highest level of evidence for increasing overall PA. This review confirms the public health potential of high quality, school-based PA interventions for increasing PA and possibly fitness in healthy youth.

Active Transport, Physical Activity, and Body Weight in Adults: A Systematic Review

CONTEXT Physical activity has various health benefits. Active transport can contribute to total physical activity and thus affect body weight because of increased energy expenditure. This review summarizes published evidence on associations of active transport, general physical activity, and body weight in adults. EVIDENCE ACQUISITION A systematic review of the literature was conducted in October 2010 using eight databases. A total of 14,216 references were screened; full texts were retrieved for 95 articles. Forty-six articles (36 unique studies) were included: 20 (17) from Europe; 18 (13) from North America, Australia, and New Zealand; and eight (six) from other countries. Analyses of the retrieved papers were carried out between November 2010 and March 2011. EVIDENCE SYNTHESIS Of 15 studies assessing active transport and physical activity, five found associations in the expected direction (more active transport associated with more physical activity) for all or most variables studied, nine found some associations, and one reported no associations. Of 30 studies assessing active transport and body weight, 13 reported associations in the expected direction (more active transport associated with lower body weight) for all or most variables studied, 12 found some associations, two presented some associations in the expected and some in the opposite direction, and three reported no associations. CONCLUSIONS There is limited evidence that active transport is associated with more physical activity as well as lower body weight in adults. However, study heterogeneity, predominantly cross-sectional designs, and crude measures for active transport and physical activity impede quantitative conclusions.

Review and special articleActive Transport, Physical Activity, and Body Weight in Adults: A Systematic Review

CONTEXT Physical activity has various health benefits. Active transport can contribute to total physical activity and thus affect body weight because of increased energy expenditure. This review summarizes published evidence on associations of active transport, general physical activity, and body weight in adults. EVIDENCE ACQUISITION A systematic review of the literature was conducted in October 2010 using eight databases. A total of 14,216 references were screened; full texts were retrieved for 95 articles. Forty-six articles (36 unique studies) were included: 20 (17) from Europe; 18 (13) from North America, Australia, and New Zealand; and eight (six) from other countries. Analyses of the retrieved papers were carried out between November 2010 and March 2011. EVIDENCE SYNTHESIS Of 15 studies assessing active transport and physical activity, five found associations in the expected direction (more active transport associated with more physical activity) for all or most variables studied, nine found some associations, and one reported no associations. Of 30 studies assessing active transport and body weight, 13 reported associations in the expected direction (more active transport associated with lower body weight) for all or most variables studied, 12 found some associations, two presented some associations in the expected and some in the opposite direction, and three reported no associations. CONCLUSIONS There is limited evidence that active transport is associated with more physical activity as well as lower body weight in adults. However, study heterogeneity, predominantly cross-sectional designs, and crude measures for active transport and physical activity impede quantitative conclusions.

Physical activity recommendations for health: what should Europe do?

BackgroundAccumulating scientific evidence shows physical activity to have profound health benefits amenable to substantial public health gains. Accordingly, recommendations on how much and what kind of physical activity enhances health have been issued. The 1995 recommendation from the U.S. Centres for Disease Control and Prevention and the American College of Sports Medicine has been adapted worldwide, including Europe. Recently an extensive review of new evidence was undertaken and refined recommendations were issued by the U.S. Department of Health and Human Services. We summarise the development of physical activity recommendations and consider the need and possible ways to update the current European situation.DiscussionThe new recommendations include several new elements when compared to the 1995 recommendation, the most notable being the greater emphasis on the contribution of vigorous-intensity activities, and the inclusion of activities for muscle strength and bone health. They also include specific recommendations for young people, middle-aged adults, older adults and some special groups. The existing Pan-European and national physical activity recommendations in Europe are mostly based on the 1995 recommendation and primarily target adults and young people. Thus the degree to which they are compatible with the new recommendations varies. In view of the growing public health importance of physical activity, we discuss the need to review the existing physical activity recommendations at the European level and assess their consistency with the new evidence and the new recommendations.SummaryWe argue that a review of the current physical activity recommendations in Europe should be undertaken in view of the most recent research evidence. We recommend that such a task should be taken on by WHO Europe in parallel with the ongoing work by WHO global Headquarters. Following this, each country should develop communication strategies and implementation guidelines that take into account their ethnic and cultural diversity.

Comparison of trial participants and open access users of a web-based physical activity intervention regarding adherence, attrition, and repeated participation

Background Web-based interventions are popular for promoting healthy lifestyles such as physical activity. However, little is known about user characteristics, adherence, attrition, and predictors of repeated participation on open access physical activity websites. Objective The focus of this study was Active-online, a Web-based individually tailored physical activity intervention. The aims were (1) to assess and compare user characteristics and adherence to the website (a) in the open access context over time from 2003 to 2009, and (b) between trial participants and open access users; and (2) to analyze attrition and predictors of repeated use among participants in a randomized controlled trial compared with registered open access users. Methods Data routinely recorded in the Active-online user database were used. Adherence was defined as: the number of pages viewed, the proportion of visits during which a tailored module was begun, the proportion of visits during which tailored feedback was received, and the time spent in the tailored modules. Adherence was analyzed according to six one-year periods (2003-2009) and according to the context (trial or open access) based on first visits and longest visits. Attrition and predictors of repeated participation were compared between trial participants and open access users. Results The number of recorded visits per year on Active-online decreased from 42,626 in 2003-2004 to 8343 in 2008-2009 (each of six one-year time periods ran from April 23 to April 22 of the following year). The mean age of users was between 38.4 and 43.1 years in all time periods and both contexts. The proportion of women increased from 49.5% in 2003-2004 to 61.3% in 2008-2009 (P< .001). There were differences but no consistent time trends in adherence to Active-online. The mean age of trial participants was 43.1 years, and 74.9% were women. Comparing contexts, adherence was highest for registered open access users. For open access users, adherence was similar during the first and the longest visits; for trial participants, adherence was lower during the first visits and higher during the longest visits. Of registered open access users and trial participants, 25.8% and 67.3% respectively visited Active-online repeatedly (P< .001). Predictors of repeated use were male sex (odds ratio [OR] = 1.2, 95% confidence interval [CI] = 1.04-1.38) and increasing age category in registered open access users, and age 46-60 versus < 30 years (OR = 3.04, 95% CI = 1.25-7.38) and Swiss nationality (ORnonSwiss= 0.64, 95% CI = 0.41-1.00) in trial participants. Despite reminder emails, attrition was much higher in registered open access users compared with trial participants, with a median lifetime website usage of 0 days in open access users and 290 days in trial participants. Conclusions Adherence, patterns of use, attrition, and repeated participation differed between trial participants and open access users. Reminder emails to encourage repeated participation were effective for trial participants but not for registered open access users. These issues are important when interpreting results of randomized controlled effectiveness trials.

Effectiveness of Active-Online, an Individually Tailored Physical Activity Intervention, in a Real-Life Setting: Randomized Controlled Trial

Background Effective interventions are needed to reduce the chronic disease epidemic. The Internet has the potential to provide large populations with individual advice at relatively low cost. Objective The focus of the study was the Web-based tailored physical activity intervention Active-online. The main research questions were (1) How effective is Active-online, compared to a nontailored website, in increasing self-reported and objectively measured physical activity levels in the general population when delivered in a real-life setting? (2) Do respondents recruited for the randomized study differ from spontaneous users of Active-online, and how does effectiveness differ between these groups? (3) What is the impact of frequency and duration of use of Active-online on changes in physical activity behavior? Methods Volunteers recruited via different media channels completed a Web-based baseline survey and were randomized to Active-online (intervention group) or a nontailored website (control group). In addition, spontaneous users were recruited directly from the Active-online website. In a subgroup of participants, physical activity was measured objectively using accelerometers. Follow-up assessments took place 6 weeks (FU1), 6 months (FU2), and 13 months (FU3) after baseline. Results A total of 1531 respondents completed the baseline questionnaire (intervention group n = 681, control group n = 688, spontaneous users n = 162); 133 individuals had valid accelerometer data at baseline. Mean age of the total sample was 43.7 years, and 1146 (74.9%) were women. Mixed linear models (adjusted for sex, age, BMI category, and stage of change) showed a significant increase in self-reported mean minutes spent in moderate- and vigorous-intensity activity from baseline to FU1 (coefficient = 0.14, P = .001) and to FU3 (coefficient = 0.19, P < .001) in all participants with no significant differences between groups. A significant increase in the proportion of individuals meeting the HEPA recommendations (self-reported) was observed in all participants between baseline and FU3 (OR = 1.47, P = .03), with a higher increase in spontaneous users compared to the randomized groups (interaction between FU3 and spontaneous users, OR = 2.95, P = .02). There were no increases in physical activity over time in any group for objectively measured physical activity. A significant relation was found between time spent on the tailored intervention and changes in self-reported physical activity between baseline and FU3 (coefficient = 1.13, P = .03, intervention group and spontaneous users combined). However, this association was no longer significant when adjusting for stage of change. Conclusions In a real-life setting, Active-online was not more effective than a nontailored website in increasing physical activity levels in volunteers from the general population. Further research may investigate ways of integrating Web-based physical activity interventions in a wider context, for example, primary care or workplace health promotion.

What physical activity surveillance needs: validity of a single-item questionnaire

Background Self-report instruments to assess physical activity are still the most feasible option in many population-wide surveys, and often need to be very short owing to resource constraints. The aim of this study was to test the criterion validity of a single-item physical activity measure using accelerometers and to compare its measurement properties by gender, age group (including older adults) and language region. Methods A validation study was carried out within the second follow-up of a large Swiss cohort study (Swiss Cohort Study on Air Pollution and Lung and Heart Disease in Adults, SAPALDIA, n=208) and included an additional convenient sample (n=110). Participants wore an accelerometer over eight consecutive days and then completed the single-item measure. Spearmans rank-order correlations were used to assess the criterion validity. Results Physical activity levels were higher in men, younger individuals and those from the German-speaking part of Switzerland. Correlation coefficients for the number of days with at least 30 min of moderate-to-vigorous physical activity according to the single item and different accelerometer activity outcomes ranged from 0.40 to 0.54. Correlations were higher for women, younger individuals and participants from the French-speaking and the Italian-speaking parts. Conclusions The single-item physical activity measure performed at least as well as other physical activity questionnaires. The differences in criterion validity between sub groups indicate that factors such as gender and age should be taken into account when developing physical activity questionnaires and in future validation studies.

Effects of a lifestyle physical activity intervention on stages of change and energy expenditure in sedentary employees.

Abstract Objectives: To assess the effects of an intervention in a worksite setting on changes in physical activity. It was expected that an intervention with an emphasis on daily life activities, such as brisk walking, would increase the proportion of individuals expending more than 1000 kcal per week in activities with at least moderate intensity, or influence individuals to change from one stage of the Transtheoretical Model of Behaviour to a higher one. Design: Quasi-experimental. Data were collected before and after a 4 month intervention period in 6 offices ( n =211) of the Swiss federal administration. Two offices ( n =168) served as controls. Methods: Participants completed a 7 day recall questionnaire on physical activities (daily life activities, leisure time activities, and sport) and stages of readiness for change, along with questions on demographic variables. Components of the intervention programme were: information, actions for daily life activities, fitness lessons, and counselling. Results: Between precontemplation/contemplation, preparation, and action/maintenance there was a significant difference of more than 850 kcal of energy expenditure. Baseline and follow-up examinations revealed a significant progression across the stages of change in the intervention offices. Subgroup analyses showed that the level of physical activity at baseline influenced the effect of the intervention. Exclusively in worksites with a lower proportion of sufficiently active individuals, the intervention was able to substantially increase the proportion by 21%. Conclusions: A diversified intervention programme in a worksite setting encourages participants to become more physically active during work and leisure time.

Evidence-based physical activity promotion - HEPA Europe, the European Network for the Promotion of Health-Enhancing Physical Activity

There has been a world-wide increase in scientific interest in health-enhancing physical activity (HEPA). The importance of a physically active lifestyle has now been well established both on the individual and on the population level. At the same time, physical inactivity has become a global problem. While sports for all has a long history, only a few examples of long-term integrated physical activity promotion strategies have been in place in Europe until recently, namely in Finland, the Netherlands and England. A number of countries have now begun to develop their own activities. However, there has been a noticeable lack of a platform for sharing the development and implementation of evidence-based policies and strategies. In order to fill this gap, HEPA Europe, the European Network for the Promotion of Health-Enhancing Physical Activity, was founded in May 2005 in Gerlev, Denmark. The goal of the network is to strengthen and support efforts and actions that increase participation in physical activity and improve the conditions favourable to a healthy lifestyle, in particular with respect to HEPA. The Network is working closely with the WHO Regional Office for Europe (http://www.euro.who.int/hepa). The network focuses on population-based approaches for the promotion of HEPA, using the best-available scientific evidence, and is currently implementing its first projects. HEPA Europe has established collaboration with EU Commission projects and Agita Mundo. Priorities for future work have been defined, and interested organisations and institutions have the opportunity to join the network and participate in the process.