Trends of low physical activity among Iranian adolescents across urban and rural areas during 2006–2011

Physical inactivity among adolescents has risen globally, with WHO recommending at least 60 minutes/day of moderate-to-vigorous activity for ages 5–17 and defining low activity as <600 MET-minutes/week. Over 80% of adolescents worldwide do not meet recommendations. In Iran, systematic reviews indicate high prevalence of physical inactivity and sedentary lifestyle among youth. Insufficient activity in adolescence is linked to unhealthy lifestyles and chronic diseases (type 2 diabetes, CVD, cancers). Adolescence is a critical period in which activity tends to decline while sedentary behaviors increase. Prior evidence shows complex associations between physical activity and weight status, with some data indicating low activity even among underweight adolescents, and gender differences showing boys are generally more active than girls. Environmental and societal factors—urbanization, technological changes, transportation—may influence activity patterns, with some studies suggesting rural adolescents spend more time in outdoor activities than urban youth. Given Iran’s predominantly urban population and limited longitudinal data, this study aimed to examine trends of low physical activity among Iranian adolescents aged 15–19 years across urban and rural areas using national SuRFNCD data from 2006–2011.

Global data show dramatic increases in adolescent physical inactivity; WHO estimates >80% of 11–17-year-olds are insufficiently active. In the Eastern Mediterranean region, only a minority meet activity recommendations, and Iranian cross-sectional studies report high inactivity and sedentary time. Associations between physical activity and weight are inconsistent: some U.S. and international studies report low activity in both underweight and overweight adolescents, and large surveys in the region show varying patterns across weight groups. Gender disparities are well documented, with girls less active than boys across multiple regions (America, Europe, China, Bangladesh, Saudi Arabia). Urbanization and technological adoption are associated with reduced daily activity and increased sedentary behavior; some studies suggest rural youth are more active than urban counterparts, though findings can be context-dependent. These mixed results underscore the need for national trend analyses by sex and residence.

Design and population: Repeated cross-sectional national Surveillance of Risk Factors of Non-Communicable Diseases (SuRFNCD) surveys (WHO STEPS-based) conducted annually from 2006–2011, except 2010. Multistage random cluster sampling yielded a representative sample of urban and rural residents. For this analysis, 12,178 adolescents aged 15–19 years were included: 2006 (n=2595), 2007 (n=2897), 2008 (n=2950), 2009 (n=2827), 2011 (n=909). Ethics approval obtained; informed consent provided; interviewers trained. Measurements: Physical activity assessed by the WHO Global Physical Activity Questionnaire (GPAQ, version 2 translation; acceptable reliability/validity). Demographics (sex, age, province, area) recorded. Height and weight measured using calibrated portable devices; BMI computed (kg/m^2). Weight status: For ages 15–18 years, BMI z-scores categorized underweight to obese; for 19–20 years, standard adult BMI categories used. For analysis, underweight+normal grouped as non-obese; overweight+obese grouped as obese. Physical activity categorization (GPAQ): High: vigorous activity ≥3 days achieving ≥1500 MET-min/week, or any combination ≥7 days achieving ≥3000 MET-min/week. Moderate: vigorous activity ≥3 days for ≥20 min/day, or moderate (including walking) ≥5 days for ≥30 min/day, or any combination ≥5 days achieving ≥600 MET-min/week. Low: not meeting criteria above (<600 MET-min/week). Statistical analysis: Complex survey analysis with sampling weights based on 2011 national census stratified by sex and area. Data pooled across years. Continuous variables summarized as mean±SE; categorical as frequencies (%). Multinomial logistic regression modeled physical activity levels with high activity as reference; year included as categorical (coded 0=2006,1=2007,2=2008,3=2009,5=2011). Model 1a adjusted for year, stratified by area; included sex and obesity status; tested sex×obesity and area×obesity interactions. Model 1b adjusted for year, stratified by sex; included area and obesity status. Prevalence ratios (PR) with 95% CIs reported. Linear regression assessed trends in total physical activity (MET-min/week) by sex and area, with interaction tests (sex×year, area×year). Unadjusted prevalence rates of low activity with 95% CIs by sex/area/year computed; linear regression tested temporal trends 2006–2011. Analyses performed in STATA v14; two-sided p<0.05 significant.

Sample: 12,178 adolescents (45.9% girls; 54.1% boys); mean age ~17 years across surveys. Trends by area (Table 1): From 2006 to 2011, high physical activity declined while low activity increased in both urban and rural areas. Urban high activity: 47.30%±1.14 (2006) to 41.41%±2.08 (2011); urban low activity: 19.74%±1.02 to 30.90%±1.87. Rural high activity: 55.04%±1.38 to 44.64%±2.85; rural low activity: 18.99%±1.18 to 28.46%±2.63. Non-obese proportion decreased and obese increased modestly in both areas over time. Multinomial models (year-adjusted):

• Sex differences within areas (Model 1a): Boys had substantially lower prevalence of low and moderate activity compared with girls. Urban: PR low 0.11 (95% CI 0.09–0.14), PR moderate 0.20 (0.17–0.25). Rural: PR low 0.11 (0.10–0.14), PR moderate 0.21 (0.18–0.24). Obesity status was not significantly associated with activity level (urban obese vs non-obese: PR low 0.99 [0.77–1.27], PR moderate 1.01 [0.80–1.27]; rural obese vs non-obese: PR low 1.06 [0.74–1.51], PR moderate 0.97 [0.68–1.36]).
• Area differences within sex (Model 1b): Rural vs urban adolescents had lower prevalence of low and moderate activity among both girls and boys. Girls: PR low 0.59 (0.47–0.74), PR moderate 0.59 (0.47–0.74). Boys: PR low 0.56 (0.43–0.75), PR moderate 0.60 (0.48–0.74). Obesity status not significant (girls obese vs non-obese: PR low 0.86 [0.65–1.14], PR moderate 0.83 [0.62–1.09]; boys obese vs non-obese: PR low 1.15 [0.84–1.56], PR moderate 1.16 [0.89–1.51]). Interaction terms (sex×obesity; area×obesity) were not significant. Total physical activity trends (Fig. 1): Significant decreases from 2006 to 2009 across both sexes and areas (p<0.05). From 2009 to 2011, total physical activity increased in boys from urban areas. No significant sex×year (p=0.3) or area×year (p=0.25) interactions. Linear trend p-values: boys 0.03; girls 0.02; urban 0.07; rural 0.04. Prevalence of low activity over time: Highest in 2011 and lowest in 2006 across both sexes and areas. Significant increasing trend in low activity from 2006 to 2011 among girls in both areas and among boys in urban areas (p<0.05).

The study addressed whether low physical activity among Iranian adolescents changed over 2006–2011 and whether trends differed by sex and residence. Findings show a nationwide rise in low physical activity, with consistent increases across urban adolescents of both sexes and among rural girls. Boys were more active than girls across both urban and rural settings, highlighting persistent gender disparities. Rural residence was associated with lower prevalence of low and moderate activity than urban residence for both sexes, consistent with hypotheses about urbanization, technological change, and sedentary lifestyles reducing activity opportunities in cities. Physical activity levels were not significantly associated with obesity status, aligning with literature suggesting multifactorial determinants of adolescent adiposity and the need to consider diet and broader behaviors. These trends indicate a growing public health concern and emphasize targeting interventions to urban youth and rural girls, addressing environmental and socio-cultural barriers to activity.

Physical inactivity among Iranian adolescents is highly prevalent and increased from 2006 to 2011 in both urban and rural areas. Boys were more active than girls, and rural adolescents were more active than urban peers. Obesity status was not associated with activity level. Policies and interventions are urgently needed to promote physical activity nationwide, with particular focus on girls—especially those in rural areas—and on urban environments that may hinder active lifestyles. Future research should explore determinants and barriers to activity in diverse settings to inform targeted strategies.

Data were not collected in 2010, creating a temporal gap. Information on specific barriers to physical activity in urban and rural areas was lacking, limiting interpretability. Physical activity was self-reported via GPAQ and collected by multiple interviewers nationwide, potentially introducing measurement and interviewer bias. Assessment of suburban areas was not feasible due to differing lifestyle patterns and cultural context.