The effect of the planned behaviour theory and the transtheoretical behaviour model on physical activity. A systematic review.


Anastasia Dermatis1, Flora Bacopoulou2,3, Ioulia Kokka2,4, Dimitrios Vlachakis3,5, Georgios Lyrakos6, Despina Menti6, Christina Darviri2

1Psychology Laboratory, CityU Research Center, Athens, Greece

2Postgraduate Course on the Science of Stress and Health Promotion, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece

3Center for Adolescent Medicine and UNESCO Chair on Adolescent Health Care, First Department of Pediatrics, School of Medicine, National and Kapodistrian University of Athens, Aghia Sophia Children’s Hospital, Athens, Greece

4University Medical School, Outpatient Specialty Clinic for Sexual Health, First Department of Psychiatry, Eginition Hospital, Athens

5Laboratory of Genetics, Department of Biotechnology, School of Applied Biology and Biotechnology, Agricultural University of Athens, Athens, Greece

6Department of Psychology, Cardiff Metropolitan University at City Unity College, Athens, Greece

Competing interests: AD none; FB none; IK none; DV none; GL none; DM none; CD none

Dermatis et al. (2023) EMBnet.journal 29, e1046 http://dx.doi.org/10.14806/ej.29.0.1046

Received: 01 May 2023 Accepted: 23 May 2023 Published: 21 September 2023


Systematic physical activity (PA) is crucial in preventing illnesses that can become life-threatening, such as colon and breast cancer, heart disease and ischemic stroke, cardio-respiratory disease, type II diabetes, and depression. Many theory–based interventions have been applied to achieve positive outcomes in an individual’s behavioural change and the ability to engage in systematic PA. This systematic review investigates the influence of the Transtheoretical model of behaviour (TTM) and the theory of planned behaviour (TPB) on PA. A substantial search in Science Direct, Wiley Online Library databases and PubMed was performed to obtain articles about the topic. Data exportation was possible after the reviewers applied exclusion–inclusion criteria to estimate evidence quality. Empirical evidence was assessed with the CONSORT checklist to appraise the risk of bias. The primary search identified 195 studies. Of those, ten original studies were comprised. All studies indicated a positive influence of TPB and TTM on physical activity in non–health and healthy populations. In particular, it was found to have an impact on energy expenditure, balance and body strength. Theory-based interventions are notably effective in promoting physical activity behaviour. Researchers and health professionals must select and utilise interventions based on the above mentioned theories and aim to enhance PA behavioural change on individual and interpersonal factors. Although the positive outcomes of theory-based interventions on PA behaviour, it is necessary for further research to be conducted.


The definition of physical activity (PA) states that it is “an activity of the body generated by the skeletal muscles which influence the enhancement of metabolic rate over resting energy expenditure” (Neufer et al., 2015). PA is a complex behaviour classified into low, moderate, and high intensity. Regulate PA is linked to considerable health benefits, such as reduced type II diabetes, breast and colon cancer, depression, ischemic stroke, and cardiovascular disease (Welch et al., 2019). Medical professionals recommend PA to relieve chronic pain significantly. It is estimated that 33% of the world’s population is affected by chronic pain (Dureja et al., 2014). Moreover, research has indicated that exercise and PA can amplify the operation of the central nervous system, reduce cognitive operational erosion associated with ageing, and decrease the possibility of dementia (Foster et al., 2018; Kennedy et al., 2017). Furthermore, PA induces neurotransmitters such as norepinephrine and serotonin, which subscribe to stress reduction (Chauvet – Gelinier and Bonin, 2017).

To reduce non – communicable diseases, the World Health Organization, under the Global Action Plan (WHO, 2017), proposed a 25% decrease in the jeopardy of premature mortality from cancer, diabetes, and chronic respiratory disease, by 2025. Numerous reports underline that a significant percentage of people worldwide cannot become involved long–term with PA (Kohl III et al., 2012). Thus, differentiating the characteristics of effective PA promotion plans has become a significant concern for public health authorities. Theory-based projects appear to be most efficacious when considering behavioural change.

Such projects are developed according to valid theories of behavioural change, which verify the assumption that behaviour moderators need to be modified to establish a behaviour change (Glanz and Bishop, 2010). A vast amount of theories have been applied to attain positive behavioural outcomes. It has been acknowledged that theory-based interventions allow scientists to collect data, test hypotheses, distinguish variables that influence behaviour, and propose mechanisms which should be included during behavioural interventions (Davis et al., 2015; Michie et al., 2014). A theoretical approach with a significant effect on behavioural change towards PA is the theory of planned behaviour (TPB). The TPB focuses on theoretical apprehensions concerning an individual’s motivational features as determinants in establishing specific behaviour (Ajzen, 2015). Furthermore, a theory-based model is highly recognised for its ability to interpret when and how individuals are willing to change their behaviour, also known as the transtheoretical model of change (TTM). The theory mainly centers on how individuals transition from one stage to the next, decisional balance, and self–efficacy. Also, TTM explores an individual’s readiness to conform to new behaviour and incorporates five behavioural change stages (Prochaska and DiClemente, 1983).

This review investigates the influence of both theories-based models on physical activity.


Study selection

Wiley Online Library databases, Science Direct, and PubMed were used to identify studies. Keywords used in the search equation were: Physical Activity (PA), Transtheoritical Model (TTM), Theory of Planned Behavior (TPB), and Exercise and Physical Activity.

Inclusive criteria: 1) studies that evaluated the effect of TPB or TTM on PA, 2) regardless of age and gender of participants, 3) randomised control trial design studies, 4) studies including non–clinical and clinical population, 5) studies including interventions, regardless of a specific structure (sequence of events, duration, location).

Exclusive criteria: 1) studies subject matter unrelated to the topic, 2) studies published in languages other than English, 3) other systematic reviews and meta-analyses, and 4) scientific protocols published providing inadequate outcomes.

Study evaluation

Specific criteria were used to assess all studies of this systematic review from the Consolidating Standards of Reporting Trial Checklist 2010 (CONSORT) (Schulz et al., 2010). Criteria required for this article were: structured abstract, eligibility of participants, sufficient sample size, number of participants allocated to groups, flow diagram, percentage of drop–outs for each group, demographics and clinical information, and limitations.


The primary search submitted 195 articles. Due to the absence of theory-based interventions, eight articles were excluded. Furthermore, thirty articles were excluded due to the absence of full-text availability. The non-reference to PA excluded forty-five articles. Lack of randomised control trial design excluded thirty articles. Finally, in this systematic review, ten articles were evaluated. The flow chart of article selection is presented in Figure 1.


Figure 1.


According to the CONSORT 2010 criteria checklist, a structured abstract was not provided for three articles (Chatzisarantis et al., 2015; Darker et al., 2010; Shirazi et al., 2007). All articles comprised eligibility criteria and pre–specified primary and secondary estimations. The sample size was determined in only half of the articles (Darker et al., 2010; Marshall et al., 2003; Jennings et al., 2014; Shirazi et al., 2007). Six articles indicated a control trial design and generation (Darabi et al., 2017; Chatzisarantis et al., 2015; Darker et al., 2010; Jennings et al., 2014; Marshall et al., 2003; Shafieinia et al., 2016). All articles identified statistical methods, while only two did not present a flow chart (Darker et al., 2010; Mostafavi et al., 2015). Participants’ withdrawal rates and losses were described in all ten articles. Two articles did not provide baseline demographic tables (Darker et al., 2010; Mostafavi et al., 2015). Limitations were indicated in all ten articles. Overall, the studies being evaluated were suitable to be incorporated in this review and are outlined in Table 1.

Table 1. Studies included in the systematic review.






Author, Year, Origin

sample, age, gender, characteristics

sample, mean age, gender

Main Outcomes

Shirazi et al., 2007, Iran

n=61, 40-65 yrs, females, general population osteoporosis prevention

n=55, females, 40-65 yrs

TTM 12-week intervention included an exercise program costumed for each participant on weight training and walking and an educational program based on individual (SoC).

The active group increased lower body strength and balance. Psychological (SoC) also showed positive progress. From being sedentary (SoC) to active.

Proper et al.,2003, Germany

n=299,males and females, over 18


Seven 20 min TTM counselling sessions structured on participants’ SoC for nine months based on PACE program measures. In addition, healthy lifestyle factors were provided to increase PA behaviour.

Increased cardiovascular capacity and energy expenditure indicated TTM interventions positively affected PA.

Pinto et al.,2005, Nertherlands

n=43, females, 18 and older, breast cancer patients

n=43, females, 18 and over, breast cancer patients

PA counseling 12 week TTM intervention based on weekly exercise info and (SoC) to enhance PA behavior.

There was a rise in moderate intensity PA levels and high energy expenditure per week after increased PA behavioral promotion.

Marshall et al., 2003, Australia

n=227, males and females, 40 – 60 yrs., general population

n=235, males and females, 40 – 60 yrs., general population.

TTM intervention included 1 time mailing of 4 brochures on PA structured on participants SoC to promote PA behavior.

Short – term PA behavior was increased after TTM intervention.

Mostαfavi et al., 2015, Iran

n=71, females, mean age 52 yrs. Metabolic Syndrome

n=71, females, mean age 52 yrs. Metabolic Syndrome

TTM Intervention consisted of five 1 hour educational sessions and exercise instructions to promote PA behavior.

TTM intervention had a positive increase in PA behavior. Lowered triglyceride, and HDL cholesterol levels.

Shafieinia et al., 2016, Iran

n=54, females, age between 18 – 60 yrs. general population

n=54, females, age between 18 – 60 yrs. general population

TTM intervention four 90’ educational sessions and e mail reminding correspondence once every 2 weeks to increase PA behavior.

TPB had major increase on PA behavior. Increase of objective to walk longer, inspired participants to indeed walk longer.

Chatzisarantis et al., 2015. Australia

n=1028, male and female adolescents, age 12 – 18 yrs. secondary students

n=344, male and female adolescents, age 12 – 18 yrs. secondary students

TPB intervention to enhance PA included reading students persuasive messages and vigorous PA four days a week for eight weeks during leisure time.

Leisure physical activity was increased and showed medium – to large change following an effective TPB intervention program.

Darker et al., 2010, Ireland, UK, Aberdeen.

n=66, male and female, age 16 – 65 yrs,general population

n=64, male and female, age 16 – 65yrs, general population

During a 77 days TPB intervention to promote PA participants committed to increase walking time 10 – 20’ each week. Intervention was based on coping planning, goal setting, and action planning.

TPB intervention significantly influenced walking behavior. Participants increased walking behavior during the week.

Jenning et al., 2014, Australia, Canada.

n=184, males and females, age <18yrs,type II diabetes

n=202, males and females, age <18yrs,type II diabetes

12-week web - based TPB intervention to increase PA.

TPB intervention changed PA behavior. A web – based programme indicated a short term change in physical activity. All PA measures, including steps per day, moderate and vigorous physical activity ,were increased.

Darabi et al., 2017, Iran.

n=289, female, age 12 – 16yrs.

n=289, female, age 12 – 16yrs.

6 months TPB intervention with 90 min educational sessions and complementary media training to increase PA behavior.

Adolescent girls improved overall PA after completing a TBA educational intervention .


Five (50%) of the studies involved TPB interventions and five (50%) of the studies involved TTM interventions. 40% of the research focused on female participants. Eight of the studies investigated adult participants, whereas two were secondary school students. Four studies investigated TPB and TTM intervention results on clinical populations diagnosed with osteoporosis, metabolic syndrome, breast cancer, and type II diabetes. The seven remaining articles focused on non–clinical population. The mean sample size was n=232.2. The smallest size was n=43, and the largest size was n=1.028.


This systematic review aims to investigate the influence of the TPB and the TTM on behavioural change concerning PA. Outcomes showed that both models were efficient in increasing PA. TTM- and TPB-based interventions positively influenced PA by incrementing fitness levels in clinical and non–clinical populations. A TTM 12 – week home–based intervention was conducted to decrease osteoporosis in female participants. The intervention included an educational program on weight training and walking. Secondary results indicated an increase in PA by showing an improvement in participants’ lower body strength and balance. Moreover, a significant benefit in psychological SoC was apparent in the experimental group but not in the control group (Shirazi et al., 2007). A different study evaluating the effect of a TTM intervention on PA indicated a significant improvement in PA by measuring the total increase in energy expenditure. Intervention periods were short and tailored for each individual on SoC. The positive increase in PA was evident in outcome measures.

According to SoC, results of the TTM 12-week intervention based on PA weekly exercise information and consultations showed a substantial improvement in PA behaviour. Differentiation among intervention and control groups showed an increase in overall time of PA at a modest – intensity per week. Moreover, the experimental group indicated a significant rise in high and very high energy expenditure over the control group (Pinto et al., 2005). The outcomes of an RCT study structured as a TTM intervention on adults showed an increase in short–term PA behaviour. The intervention included a one–time mailing of four pamphlets and a letter to a randomly distributed experimental group. The brochures were evaluated carefully to represent participants’ current SoC. At two months’ baseline the experimental group showed a significant PA increase of 78 minutes per week, whereas at six months, PA behaviour had sustained higher for the experimental group than the control group but had been reduced insignificantly compared to two months post–baseline calculations (Marshall et al., 2003). Empirical evidence in a study investigating the impact of a TTM intervention to increase PA for females with metabolic syndrome showed an increase in PA levels for the intervention group, with significant advancement in all SoC. Participants in the control group did not indicate any shift in PA behaviour. All shifts in TTM constructs were notable in the experimental group. Both exercise instructions and educational sessions positively increased PA behaviour (Mostafavi et al., 2015). The efficient outcomes of both theories are highlighted in two more studies. Scientists designed an RCT intervention based on TPB to increase PA behaviour among women. The intervention was structured on a combination of emails sent once every two weeks for three months, sent once every two weeks for three months, and four educational sessions with a duration of 90’. Results indicated an enhancement in all TPB variables, with the exception of subjective norms, and an increase in PA behaviour in the intervention group compared to the control group (Shafieinia et al., 2016). In addition, a TPB school–based intervention was designed to alter leisure–time PA behaviour. The intervention included a high-intensity 40’ PA session four days a week for eight weeks. The study outcomes revealed a shift in PA behaviour by showing a medium to high increase in PA leisure– time (Kawabata et al., 2018). A one-week TPB intervention was implemented to increase PA among the general public. The intervention aimed to promote walking based on objective measures. Results showed that brisk walking was increased from 20’ to 32’ over one week, thus indicating a significant enhancement in PA behavioural change (Darker et al., 2010).

The positive effect of the TPB on the increase of PA was also perceivable in a 12 – week web–based intervention for adults with type II diabetes. A self–management strategy was used to increase PA behavioural change. Study’s outcome by the end of the 12 weeks indicated an overall increase in PA behaviour (Jennings et al., 2014). Results were consistent with those of Baker and Mutrie, (2005). Researchers designed a four–week TTM intervention to increase PA using a pedometer. Data analysis showed a positive change in PA behaviour.

Moreover, results were consistent with those of Dinger et al., (2007), who indicated a significant PA behavioural change using a TTM web–based intervention. Also, research outcomes were consistent with those of Kawabata et al., (2018), showing an increase in leisure–time PA after completing a four–week PA intervention among secondary school students based on the TPB. In addition, Vandelanotte et al., (2007), empirically indicated an important increase in PA behaviour change utilising a web–based TPB structured intervention.

The current systematic review does not lack limitations. It is necessary to mention that 40% of the articles being evaluated had high rates of sample dropouts (Mostafavi et al., 2015; Shirazi et al., 2007; Darker et al., 2010; Shafieinia et al., 2016). Furthermore, for only a few studies, fair homogeneity was evident among participants when examining socioeconomic status and race. This factor could limit generalisation of the outcomes (Shirazi et al., 2007; Pinto et al., 2003; Darabi et al., 2017; Proper et al., 2003). Also, a significant limitation is using self–report questionnaires in all of the articles being reviewed. Worth mentioning is that the study conducted by Marshall et al., (2003) held interviews via phone. This may have as a result social desirability bias, a tendency of the respondent to answer in ways favourable to the scientist (Akbulut, 2017). Moreover, a limitation in one study designed by Darker et al., (2010) is that volunteer participants were recruited to participate in the study’s TPB intervention. Such action could develop an intervention group willing to increase walking behaviour than a group of non – volunteers who would be less accepting.


Physical activity is a significant factor in maintaining optimum health status and preventing life–threatening, non – communicable diseases. A systematical exercise program has been proven to positively affect physical and mental health. The TPB and TTM theories addressing behavioural change have been applied to modify individuals’ positions towards PA. The outcomes of the current review indicated that both theoretical models positively enhance PA for non–healthy and healthy populations. However, all studies showed promising results, the fact that the sample sizes were small dictates that scientific outcomes cannot be generalised. Future studies should aim for a greater number of participants, which would increase the opportunity to generalise the findings.

Key Points

Regular physical activity can prevent mental and physical health issues.

Behavioural theory-based models can affect an individual’s behaviour.

The theory of planned behaviour and the transtheoretical model of behaviour can alter behaviour and increase physical activity.

Larger sample sizes are required for research.



This systematic review did not receive any specific grant from funding agencies in the commercial, public, or not-for-profit sectors.


Ajzen I (2015) The theory of planned behaviour is alive and well, and not ready to retire: a commentary on Sniehotta, Presseau, and Araújo-Soares. Health psychology review 9(2), 131-137. http://dx.doi.org/10.1080/17437199.2014.883474

Akbulut Y, Dönmez O, Dursun ÖÖ (2017) Cyberloafing and social desirability bias among students and employees. Computers in Human Behavior 7(2), 87-95. http://dx.doi.org/10.1016/j.chb.2017.02.043.

Baker G, Gray SR, Wright A, Fitzsimons C, Nimmo M et al. Scottish Physical Activity Research Collaboration (SPARColl) (2008) The effect of a pedometer-based community walking intervention” Walking for Wellbeing in the West” on physical activity levels and health outcomes: a 12-week randomized controlled trial. International Journal of Behavioral Nutrition and Physical Activity 5, 1-15. http://www.ijbnpa.org/content/5/1/44

Neufer P D, Bamman MM, Muoio DM, Bouchard C, Cooper et al. (2015) Understanding the cellular and molecular mechanisms of physical activity-induced health benefits. Cell metabolism 22(1), 4-11. http://dx.doi.org/10.1016/j.cmet.2015.05.011

Chatzisarantis NLD, Kamarova S, Kawabata M, Wang, JCK (2015) Developing and evaluating utility of school-based intervention programs in promoting leisure-time physical activity : An application of the theory of planned behaviour. International Journal of Sport Psychology 46(2), 95-116. http://hdl.handle.net/10497/17251

Chauvet-gelinier J, Bonin B (2017) Science Direct Stress , anxiety and depression in heart disease patients : A major challenge for cardiac rehabilitation. Annals of Physical and Rehabilitation Medicine 60(1), 6–12. http://dx.doi.org/10.1016/j.rehab.2016.09.002.

Darabi F, Kaveh MH, Majlessi F, Farahani FKA, Yaseri M et al. (2017) Effect of theory-based intervention to promote physical activity among adolescent girls: a randomized control trial. Electronic physician 9(4), 4238. http://dx.doi.org/10.19082/4238

Darker CD, French DP, Eves FF (2010) An intervention to promote walking amongst the general population based on an “extended” theory of planned behaviour: a waiting list randomised controlled trial. Psychology of Health 25(1), 71–88. http://dx.doi.org/doi:10.1080/08870440902893716.

Davis R, Campbell R, Hildon Z, Hobbs L, Michie S (2015) Theories of behaviour and behaviour change across the social and behavioural sciences: a scoping review. Health psychology review 9(3), 323-344. http://dx.doi.org/10.1080/17437199.2014.941722

Dinger MK, Heesch KC, Cipriani G (2007) Comparison of two email-delivered, pedometer-based interventions to promote walking among insufficiently active women. Science of Medicine and Sports 10(5), 297–302. http://dx.doi.org/doi:10.1016/j.jsams.2006.07.011.

Dureja GP, Jain PN, Shetty N, Mandal SP, Prabhoo R et al. (2014) Prevalence of chronic pain, impact on daily life, and treatment practices in India. Pain Practice 14(2), E51-E62. http://dx.doi.org/10.1111/papr.12132

Foster C, Shilton T, Westerman L, Bull F (2018) World Health Organisation to develop global action plan to promote physical activity: time for action. British Journal of Sports Medicine 52, 484–485. http://dx.doi.org/10.1136/bjsports-2017-098070

Glanz K, and Bishop DB (2010) The role of behavioral science theory in development and implementation of public health interventions. Annual review of public health 31, 399-418. http://dx.doi.org/10.1146/annurev.publhealth.012809.103604

Jennings CA, Vandelanotte C, Caperchione CM (2014) Effectiveness of a web-based physical activity intervention for adults with Type 2 diabetes-a randomised controlled trial. Preventive Medicine 60,33–4. http://dx.doi.org/doi:10.1016/j.ypmed.2013.12.011.

Kawabata M, Chua K, Chatzisarantis NL (2018) A school-based intervention program in promoting leisure-time physical activity: trial protocol. BMC public health 18(1), 1-7. http://dx.doi.org/10.1186/s12889-018-5320-1

Kennedy G, Hardman RJ, Macpherson H, Scholey AB (2017) How Does Exercise Reduce the Rate of Age-Associated Cognitive Decline ? A Review of Potential Mechanisms. Journal of Alzheimer’s disease 55,1–18. http://dx.doi.org/10.3233/JAD-160665.

Kohl HW, Craig, CL, Lambert EV, Inoue S, Alkandari JR et al. (2012) The pandemic of physical inactivity: global action for public health. The lancet 380(9838), 294-305. http://dx.doi.org/10.5167/uzh-69552.

Marshall AL, Bauman AE, Owen N, Booth ML, Crawford DMB (2003) Population-based randomised controlled trial of a stage-targeted physical activity intervention. Annals of Behavioural Medicine 25(3), 194–202. http://dx.doi.org/doi:10.1207/S15324796ABM2503_05.

Michie S, West R, Campbell R, Brown J, Gainforth (2014) ABC of behaviour change theories (ABC of behavior change): An essential resource for researchers, policy makers and practitioners. Silverback Publishing (Silverback IS).

Mostafavi F, Ghofranipourm F, Feizi A (2015). Improving physical activity and metabolic syndrome indicators in women: a transtheoretical model-based intervention. International Journal of Preventive Medicine 6(28). http://dx.doi.org/doi:10.4103/2008-7802.154382.

Pinto BM, Frierson GM, Rabin C, Trunzo JJ (2005) Home-based physical activity intervention for breast cancer patients. Journal of Clinical Oncology 23(15), 3577–3587. http://dx.doi.org/doi:10.1200/JCO.2005.03.080.

Prochaska JO, DiClemente CC (1983) Stages and processes of self-change of smoking: toward an integrative model of change. Consulting Clinical Psychology 51(3), 390–395. https://psycnet.apa.org/doi/10.1037/0022-006X.51.3.390

Proper KI, Hildebrandt VH, Beek AJ, Van Der, Twisk JWR (2003) Effect of Individual Counseling on Physical Activity Fitness and Health A Randomized Controlled Trial in a Workplace Setting. American journal of preventive medicine 24(3), 218–226. http://dx.doi.org/10.1016/S0749-3797(02)00645-1.

Schulz KF, Altman DG, Moher D (2010) CONSORT 2010 statement: updated guidelines for reporting parallel group randomised trials. Journal of Pharmacology and pharmacotherapeutics 1(2), 100-107. http://dx.doi.org/10.4103/0976-500X.72352

Shafieinia M, Hidarnia A, Kazemnejad A, Rajabi R (2016) Effects of a Theory Based Intervention on Physical Activity Among Female Employees : A Quasi-Experimental Study. Asian journal of sports medicine 7(2) http://dx.doi.org/10.5812/asjsm.31534

Sharabi A, Margalit M (2011) The mediating role of internet connection, virtual friends, and mood in predicting loneliness among students with and without learning disabilities in different educational environments. Journal of Learning Disabilities 44(3), 215–227. http://dx.doi.org/10.1177/0022219409357080.

Shirazi K, Wallace LM, Niknami S, Hidarnia A, Torkaman et al. (2007) A home-based , transtheoretical change model designed strength training intervention to increase exercise to prevent osteoporosis in Iranian women aged 40 – 65 years : a randomised controlled trial. Health Education Research 22(3), 305–317. http://dx.doi.org/10.1093/her/cyl067.

Vandelanotte C, Spathonis KM, Eakin EG, Owen N (2007) Website-delivered physical activity interventions: A review of the literature. American journal of preventive medicine 33(1), 54-64. http://dx.doi.org/doi:10.1016/j.amepre.2007.02.041.

Welch WA, Strath SJ, Brondino M, Walker R, Swartz AM (2019) Duration–Response of Light-Intensity Physical Activity and Glucose Dynamics in Older Adults. Journal of Physical Activity and Health 16(1), 37–42. http://dx.doi.org/10.1123/jpah.2017-0557.

World Health Organization. (2017). Preventing noncommunicable diseases (NCDs) by reducing environmental risk factors (No. WHO/FWC/EPE/17.01). World Health Organization. https://tumourclassification.iarc.who.int/


  • There are currently no refbacks.