Run-Work-Sleep-Repeat: 24/7 monitoring for healthy running

FUNDING

• The Netherlands Organization for Scientific Research (NWO)

PARTNERS

• 2M Engineering

• Golazo Sports

• Inno Sports Lab

• City of Eindhoven

• Fontys University of Applied Sciences

• School of Sport Studies

BACKGROUND

The prevailing lifestyle in the Western world (immobility, unhealthy eating, smoking and drinking habits) is an important factor in the etiology of many chronic diseases. Physical activity through sports participation helps to reduce this risk but introduces new risk factors associated with exercise related injuries. The aim of the program ‘Citius, Altius, Sanius’ is to stimulate people at all performance levels to engage in and sustain physical activity through sports and fitness, improve their performance and prevent injuries by providing informative and motivating information using advanced sensor and data science techniques. The information provided is tailored to the individual user, by taking into account his or her characteristics, and by using effective, personalized feedback methods. Innovative unobtrusive wearable sensors (in clothing, and advanced cameras) will be used to estimate the mechanical and physiological load. Data science techniques will relate the load to injury mechanisms and provide an individual training advice to stimulate the athlete and prevent injuries or return to sports and exercise quicker. Six applied projects are defined incorporating the activities that are associated with most injuries. Sports associations, sports medicine and physical therapy, but also many small-to-medium-sized companies are involved to commercialize this innovative approach for recreational and elite athletes, but also for rehabilitation patients.

Physical activity is the best medicine to prevent health problems across the lifespan: it is more efficient than cure or rehabilitation, both from a health and an economic perspective. The goal of the present program is to stimulate people to start and continue participating in sports by providing motivational and informational cues about their performance, using (big) data science and unobtrusive sensor technology. Simultaneously, personalized information, based on a combination of individual and cohort data, will be provided to recreational and elite athletes to reduce the risk of injury and overload. There is a clear trend towards individualized sports participation. Tailoring information to individual needs concerning physical activity is therefore crucial. Modern sensor technology and data science, as well as web solutions and apps like Strava, provide opportunities for obtaining this tailored information. The internet enables comparison with peers of the same age, gender, experience, training and performance objectives, etc., as well as the full history of previous performances in the cloud. Knowledge about performance improvement is a highly stimulating factor that contributes to lasting engagement and attaining higher performance levels.

The challenges in promoting healthy participation in physical exercise are twofold: (1), to provide engaging information about the athlete’s physical and performance improvement, and (2) to ensure that no injuries will occur. Although injuries prevail in many sports (see Section 4.1), little is known about their relationship with physical load.

Hence, there is a clear need to strengthen the information chain from sensor information, via data science and analysis, to informative feedback applications, which we will pursue in three fundamentally oriented projects. This not only requires innovative research regarding each of these components, but also regarding the effectiveness of the resulting information chains. For the latter purpose, we will perform research in six sports-related domains with a high prevalence of injuries. The general relationship between physical exercise and injury incidence in these domains will be investigated by acquiring large amounts of data using new sensor technology and will then be tuned to individual athletes using their individual data. The resulting individualized information will be fed back to the athlete to improve performance in a healthy manner. The feedback in question will be based on novel technological possibilities, including virtual and augmented realities, as well as novel psychological insights into mechanisms of behavioral changes.

Within each of the fundamental projects, innovative devices or mathematical approaches will be developed. Within the applied projects, these innovations will be combined, and applied to six different sport specific domains to motivate athletes and improve their performance, as well as to prevent injuries. This general approach adopted in the program as a whole is unprecedented, both in terms of its interdisciplinary and translational nature and in terms of its scale and scope.

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Who Stays Fit?

FUNDING

• SIA RAAK

• NWO Comenius

PARTNERS

• Codarts Rotterdam

• Amsterdam University of Applied Sciences

BACKGROUND

Sport injuries are one of the main causes of poor physical performance and physical discomfort in sport active populations. Physical Education Teacher Education (PETE) students are sport active population who are, as part of their education and besides their own sport participation, confronted with curricular sport participation of approximately eleven hours a week in six different sports. Due to this high amount and variety of additional sport participations PETE students have a relative high sport incidence. Therefore this population is very suitable for research on the etiology of sport injuries and provides need for the development and implementation of preventive interventions. The main goal of the ‘Who stays fit’ project is to increase insight in the incidence and etiology of sport injuries of PETE students. Within this project we research the incidence of sport injuries, risk factors of medial tibial stress syndrome, risk factors of ankle injuries, psychological risk factors of injuries, injury mechanisms, and the prevention of sport injuries.

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Long term effects of marathon running on cardiac health

FUNDING

• Indonesia Endowment Fund for Education

BACKGROUND

In the last two decades, there has been a dramatic increase in the number of athletes training for and participating in organized and recreational long-long-distance running, such as marathons. However, while the beneficial cardiovascular effects long-distance running are well documented, little is known about potential negative cardiac effects of long-term repetitive marathon running. Observational data have shown elevated cardiac markers among marathoner runners, leading to the hypothesis that myocardial injury due to prolonged hypoxemia might take place, potentially leading to myocardial fibrosis (MF), but with a highly variable incidence. There is an urgent need for awareness among runners of potential detrimental cardiac effects of long-distance running.

OBJECTIVES

To assess the proportion of subjects who has myocardial fibrosis using late gadolinium enhancement (LGE) on cardiac magnetic resonance imaging (MRC) among long term (> 5 years) marathon runners, compared to sedentary age matched controls.

RESEARCH QUESTIONS

Does repetitive long term marathon running cause myocardial fibrosis?

STUDY DESIGN

Case control study in a defined specific endurance running population compared to a matched controls. Consecutive sampling is used for the exposed subjects who meet the inclusion criteria. Dose of training (kilometers), participation hours, and cardiac findings (LGE on MRI) will be taken for analysis.

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Injury incidence and patterns in U10-U15 soccer players

FUNDING

PhD fellowship fundamental research of Research Foundation Flanders (FWO), Belgium

PROJECT PARTNERS

• Vrije Universiteit Brussel (Belgium)

• Ghent Univeristy (Belgium)

BACKGROUND

The development of youth soccer players in the academies of professional clubs involves specialized training from a very young age onwards. These development programs characterized by their high training loads and high training frequency, are developed to prepare talented young players for the increasing demands of contemporary professional match play. Football is a complex contact sport, characterized by intermittent, explosive actions, and is associated with a high risk of acute and overuse injuries in elite level youth players. Injury incidence and risk factors are well known in older adolescent and adult players, but these are thought to be different in (pre)pubertal players due to a different susceptibility of the immature muscular-skeletal system. Moreover, during puberty, players appear to be even more susceptible for injuries due to the changing body proportions and physical characteristics, as well as the temporary motor awkwardness associated with the adolescent growth spurt. 

To date, epidemiological research in (pre)pubertal elite level football players from 9 to 15 years of age is limited and often faces methodological shortcomings leading to inconclusive evidence. Also, the determinant role of growth, maturation, physical fitness and motor coordination in the risk for sustaining injuries is not fully understood. Therefore, the overall aim of this three-year large scale prospective cohort study in Belgian U10 to U15 elite level football players, is to provide a detailed overview of the injury incidence and patterns. Furthermore, the risk for sustaining injuries in relation to growth, maturation, physical fitness, and motor coordination will be investigated in detail using different, state-of-the art methods of analysis. 

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CHOiCE: Choosing the Healthy Option in a Choice Environment

FUNDING

Internal funding from the Department of Public and Occupational Health, VU University Medical Center

BACKGROUND

Technological and economic advances in the past decades have nowadays resulted in people living a lifestyle that is characterized by high rates of sitting and low levels of physical activity,  which increases people’s risk for non-communicable diseases. A promising approach to change health behaviors is the use of ‘choice architecture’. The term refers to practice of influencing behaviors by organizing the context in which people make choices. 

The aim of the CHOiCE project is to investigate which choice architecture interventions effectively (1) foster active health choices (that engender commitment towards specific health goals); and (2) support maintenance of health behaviors (by promoting habit formation), with choices and behaviors being in line with individuals’ beliefs, needs, values and preferences. The project focusses on two different populations: (a) sedentary, physically inactive healthy individuals and (b) individuals at increased risk for cardiovascular disease. 

The project consists of three main stages, with each new stage building on the insights derived in the previous stage(s):

1. A systematic literature review on choice architecture interventions that promote physical activity and discourage sedentary behavior;

2. Qualitative studies on people’s beliefs, needs, values and preferences in the context of choices about health behavior;

3. Quantitative, experimental proof-of-principle studies on the effects of different types of choice architecture.

 The ultimate aim of the project is to empower people to make healthy choices and to engage in health behaviors in the long term.  

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Injuries and their aetiology in Physical Education students

BACKGROUND

Worldwide many students participate in physical activity and sports related studies. During the course of these studies a high level of physical activity and exercise skills is demanded. In physical education teacher education (PE) studies, during the first three years on average more than 250 hours per year are spent on practical sports classes. In addition, most PE students participate in extracurricular sports as well. Therefore, these students are at high risk of sustaining a sports injury during the course of their studies. Recent studies covered injuries during the freshman year only. 

This research project covers the first two steps of the “sequence of prevention” in PE studies.

The first aim is to describe the prevalence of injuries during the first three years of PE studies and to compare injury risks between curriculum periods (years and semesters) and between sexes in PE students. Injuries in PE students over the period 2000-2014 are investigated for this purpose. 

The second aim of this project is to identify possible risk factors for injuries in PE students. In a three-year prospective cohort study, intrinsic and extrinsic risk factors for injuries in freshman PE students are investigated. In a qualitative study, the perspectives from PE students on risk factors for injuries during the first three years of their study are investigated from a socio-ecological perspective.

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The value of data science and machine learning for sports medicine clinical decision making

PROJECT PARTNERS

·      Universidade Federal de Minas Gerais

·      Arsenal Football Club

BACKGROUND

In football, the incidence of muscle injuries remains high, despite several studies on their aetiology and prevention (Ekstrand et al., 2011). Traditionally, the investigation of risk factors for sports injuries has concentrated on linear and unidirectional causality (Arnason et al., 2004, Gabbe et al., 2006 and Engebretsen et al., 2010). However, injury (and muscle injury included) arises from the complex interaction among a web of determinants. This approach can be useful in an attempt to understand the sports injury aetiology and it may allow mapping of the interactions among potential risk factors and allow the development an athlete's ‘risk profile’ (Bittencourt et al., 2016). 

Data analysis will be performed using alternative approaches; (1) Classification and Regression Trees (CART), which captures nonlinear relationships between predictors and produces results easily applied in clinical practice; and (2) Direct acyclic graphs (DAG) that allows systematic representations of causal relationships and validates the CART outcomes.

The aim of this research project is to identify a web of determinants to better understand how and why muscle injuries may occur in elite football players

“Who me?! I thought you’d never ask”: Listening and analyzing injury prevention behaviors in elite sports context

FUNDING

Caroline Bolling is a PhD candidate supported by Conselho Nacional de Desenvolvimento Científico e Tecnológico – CNPq , Brazil- grant number 202242/2015-3

BACKGROUND

Sports injury prevention researchers have developed many strategies to prevent injuries in the past years. Despite the evolution in research, how to apply the models/ programs from research into practice remains a challenge. The interventions are usually developed from the researcher’s perspective and despite having the injury prevention as the main goal, they don’t take into consideration the elite sports context and its particularities. A better understanding of this context is needed to developed customized interventions and improve the use of injury prevention strategies in practice. Qualitative methods can provide a contextual perspective on the injury problem by exploring different perpectives and enabling a more comprehensive understanding of the injury prevention process in practice. 

 RESEARCH QUESTIONS/OBJECTIVES

This project aims to recognize and understand the reality of the elite sports context through a qualitative study. We aim to explore and understand the beliefs, attitudes and knowledge about injury prevention from the athletes’ and other stakeholders’ (i.e. coaches and medical staff) perspective. 

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Head in the Game - a multicenter project on long-term health in elite female football players

PROJECT PARTNERS

· This project is a multicentre study coordinated by the MSH Medical School Hamburg, Germany.

· VU University Medical Center Amsterdam, The Netherlands.

· Swiss Concussion Center, Zurich, Swizterland.

· Hôpitaux Universitaires de Genève, Geneva, Switzerland.

· Paderborn University, Paderborn, Germany.

FUNDING

· The study was funded by the Fédération Internationale de Football Association (FIFA)

BACKGROUND

While many studies have investigated acute football injuries, few have evaluated long-term health consequences of a professional football career. Among the few studies in this area most are related to osteoarthritis and focused on male players. However, it is known that female football players are more prone to ACL injury than their male counterparts, which is a key risk factors for developing arthritis in elite athletes. Currently, there is no data regarding the prevalence and risk factors for arthritis in female football players.

Other possible long-term health sequelae that have recently received attention in the literature are neurocognitive impairments following a contact sport career. Particularly, the potential association of (sub)concussive head impacts/injuries on the development of long-term neurological deficits remains controversial. However, with several studies supporting these considerations, public concern regarding the short- and long-term adverse effect of football play on cognitive function has grown. Given the popularity of the sport, this concern may have far-reaching implications for sports participation and emphasises the need to intensify our efforts in clarifying the ongoing debate.

OBJECTIVES

The aim of the study is to evaluate and improve long-term health in elite athletes. A particular focus of the study is the long-term effect of a professional football career on the musculoskeletal system and cognitive performance in former players. In order to analyse these research questions, the project is organised in two phases. In a first step, data on current mental and physical health, wellbeing and football-related injury history in retired football players will be collected using an anonymous online questionnaire. In a clinical follow-up study and based on the results from phase 1, we will investigate the association between previous injuries and long-term health in detail using different examination methods, such as neuropsychological testing, neuroimaging, knee MRI and standardised questionnaires.

FURTHER INFORMATION

For further information and current updates on the project please refer to our website: http://hitg.study

Reduced Achilles Pain study

TITLE

"Effectiveness of a 12-week self-myofascial release therapy on pain and tendon stiffness in active recreational runners with self-reported Achilles tendon complaints"

BACKGROUND

Pain and stiffness of the Achilles tendon are a common running-related injury (RRI). One of the standard exercises in treating the complaints are eccentric exercises (ECC). It requires muscle activation thus focusing on the calf muscles. Anatomically, the Achilles tendon not only fuses with the calf muscles but has a fibrous connection with the plantar foot, the aponeurosis plantaris. Targeting not only the calf muscles but also the aponeurosis, sely-myofascial release (SMR) represents a good option for multifocal treatment. SMR has become more popular the last years. It is thought to it stimulate collagen I production and reverse pathological neovascularization. Moreover, although evidence is scarce so far, SMR has been described to loosen fascial adhesions and cross-links, increase the gliding capacities of connective tissue layers, decrease muscle tension and to alter mechanical stiffness. SMR does not impede athletic performance. It has also been suggested that SMR might have, as all manual therapies, a potentially pain-relieving effect. These analgesic effects may be mediated by either peripheral, spinal or supra-spinal mechanisms. All of the above mentioned processes might help to restore physiological tendon function.

OBJECTIVES

The purpose of this study will be to evaluate the effectiveness of a multifocal SMR treatment (directed to plantar aponeurosis, Achilles tendon and calf muscles) on pain and stiffness compared to ECC in active recreational runners with self-reported Achilles tendon complaints. 

RESEARCH QUESTIONS

Is a 12-week multifocal SMR treatment more effective in treating Achilles tendon complaints than ECC in active recreational runners?

STUDY DESIGN

Single blinded, randomized pilot study using a 2 group design with a treatment period of 12 weeks.

"Disagevantage": The influence of chronological and biological age on sport participation in children - a public health issue?

FUNDING

• “Early Postdoc Mobility fellowship” from the Swiss National Science Foundation (SNSF)

PROJECT PARTNERS

• PD Dr. Oliver Faude, University of Basel, Switzerland

BACKGROUND

Physical activity provides many positive effects on health risk factors, skeletal and psychological health, as well as on mental, cardiorespiratory and neuromuscular fitness. Physical inactivity is one of the leading causes of chronic diseases, contributing to disability and death worldwide. Active participation in organised youth sport is positively associated with higher levels of adult physical activity. Hence, youth sport also has important implications for long-term individual health as well as public health. Children like to compete against each other. Therefore, having fun during sport participation is often linked to having success. Unfortunately, not all children have the same chance to be successful in sport. As children are growing rapidly, small differences in age can cause large differences in biological development. In the sport setting children are grouped according to their birth date using cut-off-dates. In consequence, some children in a sport team might be one year younger than others and therefore they might be smaller, weaker, and less successful. In addition, some children are early- and some are late-maturing which also can lead to performance differences in the sport setting. Hence, both aspects could lead to large differences in motor performance. Therefore, a considerable amount of children might be disadvantaged just by being born at the “wrong time of the year” and/or being late-maturing. This can lead to disappointments, loss of motivation, and drop-out from sport. Data from high-level competitive sport show that the aforementioned effects lead to a clear underrepresentation of such disadvantaged children. However, data from recreational and low-level competition sport are completely missing. This is surprising as most children are participating in low-level and recreational sport. In consequence, this might relate to a relevant public-health issue.

RESEARCH QUESTIONS

• Does the time of birth within a year (i.e. "relative age") and/or the maturity status influence motor performance, sport participation, and physical activity levels in school children?

Disability football: sports injury epidemiology, injury prevention review, attitudes to concussion guidelines and concussion guideline synthesis.

BACKGROUND

Fifteen percent of the world’s population live with disability, and many of these individuals choose to play sport. There are barriers to sport participation for athletes with disability and sports injury can greatly impact on daily life, which makes sports injury prevention additionally important.

OBJECTIVES

The purpose of this project is to review the definitions, methodologies and injury rates in disability sport, which should assist future identification of risk factors and development of injury prevention strategies. A specific focus lies on concussions in disability sports. A secondary aim is to highlight the most pressing issues for improvement of the quality of injury epidemiology research for disability sport.

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European Fans in Training (EuroFIT); Social Innovation to improve physical activity and sedentary behaviour through elite European football clubs

FUNDING

European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement no 602170.

PROJECT PARTNERS

• University of Glasgow (UK)

• Norwegian School of Sports Sciences (Norway)

• Technical University of Lisbon (Portugal)

• Radboud University, Nijmegen Medical Centre

• KU Leuven

• Pintail Ltd

• PAL Technologies Limited

• European Healthy Stadia Network CIC

PROJECT WEBSITE

www.eurofitfp7.eu

BACKGROUND

20 million fans attend top division football games each week and many more watch on TV. Our aim is to attract these men, specially targeting low-SES men who do not achieve current recommendations for physical activity, to lifestyle change through the personal connection and loyalty to the club they support using the European Fans in Training (EuroFIT) programme. EuroFIT is informed and inspired by the Scottish FFIT programme, which validated several of the key concepts that underpin this project.

This project integrates two technologies within the EuroFIT programme. The first is a novel device (SitFIT) that allows self-monitoring of objectively measured sedentary time and physical activity through real-time feedback. SitFIT will be a low-cost device with an integrated display. The second is a game-based mobile-phone app, MatchFIT, in which players form ‘teams’ to participate in an ‘alternative MatchFIT league’ which mirrors fixtures in real football leagues. These technologies will be integrated into the new lifestyle change programme, EuroFIT, to be delivered in football club grounds by club coaches. 

The project will generate research evidence on the use of social innovation for health. Social impact will include reductions in health risk, improvements in well-being and the decreased inequalities as more men, especially those in low SES groups, are attracted to lifestyle change. Research impact will utilise new understanding of the how health indicators respond to change in sedentary behaviour and physical activity and through new knowledge of long-term maintenance of lifestyle changes. Policy impact will result from the production of clear implementation strategies and involvement of policy makers and opinion leaders from the outset, supported by a targeted communication strategy.

OBJECTIVES

• Use State of the Art Theory and Evidence: To apply state-of-the-art theory and evidence on motivating and maintaining behavioral change to develop a technology-supported, culturally- and gender-sensitized lifestyle programme for men, to be delivered in top European football clubs.

• Deliver EuroFIT in 15 Clubs: To deliver the EuroFIT programme in 15 leading football clubs across Europe and evaluate it in a pragmatic randomized controlled trial.

• Review and Evaluate: To review and evaluate the programme in terms of experience of: a) its benefits (or harms) to participants; b) its benefits to families and wider social networks; and c) how best to refine the programme to make it most attractive to women, families and other groups.

• Replication and Implementation: To maximize the likely implementation of EuroFIT beyond the funded project by developing detailed, validated guidelines on replication and implementation.

METHODS

This is a two arm, stratified, individually randomized, pragmatic, controlled trial with an accompanying process evaluation across 4 European countries. The trial will be conducted at 15 football clubs in Portugal, Norway, the Netherlands and England (UK). In each country, 60-80 participants will be recruited.

Using a mixed-methods, interdisciplinary approach the project will measure outcomes objectively, assess short-term cost-effectiveness and estimate long-term cost-effectiveness. We will investigate mediators of changes in health behaviours, and whether changes in lifestyle are themselves mediators of changes in clinically-measured risk factors, so that we can better understand pathways to improved physical health. We shall assess potential moderators of any effects of EuroFIT, to identify subgroups of the population for whom the programme is more or less beneficial. EuroFIT’s potential to impact on and attract other groups, particularly women and families, will be explored via qualitative research methods.

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Krajicek Playgrounds: Improving physical activity in adolescents in deprived urban neighbourhoods

PROJECT PARTNERS

• Richard Krajicek Foundation

FUNDING

This project is funded through The Netherlands Organisation for Health Research and Development (ZonMw); project number 200120009. ZonMw funds health research and stimulates use of the knowledge developed to help improve health and healthcare in the Netherlands.

BACKGROUND

The health benefits of an active and fit lifestyle are well established. Thereby, sedentary lifestyle habits are a major international and national Public Health (PH) problem. A recent study in the Netherlands revealed that less than 10% of the children in primary schools (ages 4 through 11 years) meet 30 minutes of physical activities (PA) per day, while the guidelines state a minimum of 60 minutes of PA per day for children in this age range. Although between the ages 12 and 17 this percentage triples to 27% according to 'Statistics Netherlands', the number of adolescents meeting the minimal required dose of daily PA remains unacceptably low. Looking at the current low PA rate in children, the PA rate in adolescents may only decrease in the near future. Based on these percentages it has been estimated that in 2015 one out of five adolescents is overweight. In addition, this increase is not linear, but exponential. It has become quite clear from the seriousness and extent of the current problem of overweight and insufficient PA, its rapid and exponential proliferation and its far-reaching consequences that action must be taken in stimulating adolescents are to be more physically active. Obesity is difficult to treat, which is why the preference lies with prevention of overweight and obesity. Although overweight and obesity are health problems that are ‘hot’, low levels of PA during adolescence have additional serious health consequences at later ages as well, e.g. coronary heart disease, osteoporosis, diabetes, cancer and mental illness. With the current low levels of PA in adolescents, the presently seen health problems associated with a lack of PA will only increase in the near future. This compromises the current and future health and well-being of the population, and makes promotion of PA in adolescents a major PH priority.

Previous ‘pilot’ research in the United Kingdom in children aged 4-11 years, suggested that the physical alteration of a school’s playground significantly increased children’s participation in moderate and vigorous physical activities on both the short-term and long-term. In addition it was found that children who were less active at baseline benefited more from this intervention than their more active peers. This strongly indicates that altering a school’s physical environment, based on the needs and demands of the school-going population, indeed affects PA levels in a positive way. Therefore, more research is warranted to validate these previous important findings into other (Dutch) school settings as well.

In general, schools have been recognized as key settings in promoting PA. Next to the home, the school is the environment where adolescents spent most of their time. Within the school, physical education lessons represents the main context in which adolescents have the opportunity to be physically active. Next to such structured and frequent PA opportunities, schools can cater irregularly for sporting days and other extracurricular activities. For the promotion of PA in the secondary school setting, interventions targeted at structural environmental changes have an important advantage over other interventions. Most PA provided by the school is on an irregular and/or non-daily basis. By altering the physical environment of a school’s grounds the adolescent is continuously exposed to PA possibilities. These changes then, of course, need to provide a continuous, appealing, challenging and socially safe PA environment. If this can be achieved all adolescents have the opportunity to be physically active each single day.

In the Dutch setting, as in general, overweight and obesity, it’s associated negative consequences on health, as well as a lack of sufficient PA is mostly being reported in neighborhoods in which the population of immigrants is relatively high and/or socio-economic status of the population is low.  Amongst others, this is suggested to be mostly due to the little PA possibilities imposed by the infrastructural lay-out of these urban neighborhoods. In addition, low levels of participation in organized sports are suggested to be related to membership costs which may provide an important barrier for the inhabitants of deprived neighborhoods. Even so, a large group of girls living in these neighborhoods may not participate in organized sports and PA due to their religious beliefs. The ability to give adolescents in such neighborhoods the opportunity to be physically active on a daily basis has a great potential PH gain. For that reason it is important to investigate the effect of changes in the physical environment of secondary VMBO schools situated in these neighborhoods. If effective, the alteration of the physical school environment may provide a relatively simple, continuous, and long lasting PA intervention that is openly available for the entire target population.

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