Sociodemographic factors associated with physical activity in Mexican adults.

OBJECTIVE: To estimate the physical activity level among Mexican adults and to establish the sociodemographic variables that may be linked to active lifestyles.
DESIGN: Data from a cross-sectional survey were analysed. Physical activity was assessed using the short version of the International Physical Activity Questionnaire. The independent variables were sex, age, socio-economic status and size of town. Ordinal regression models were fitted to assess the association of physical activity levels with sociodemographic factors.
SETTING: Fieldwork was conducted from November 2002 through April 2003; the non-response rate was 3.1%.
SUBJECTS: Data from a national representative sample (n 38,746) of Mexican adults aged >18 years old were analysed.
RESULTS: Almost 60% of the population was classified into the high physical activity level. Women were less active than men in rural areas; in urban areas, the opposite trend was observed. In women, higher socio-economic status was associated with less physical activity, while among men there were no differences. People from rural and urban areas had a higher probability of engaging in physical activity than those from cities. In urban localities and cities, respondents of low socio-economic status had a lower probability of engaging in physical activity.
CONCLUSIONS: Using a validated instrument to measure physical activity, we found that the prevalence of active lifestyle among Mexican adults was high. The socio-economic and gender inequalities are different according to size of town (i.e. an effect modifier), which must be considered in the design of policies and programmes to promote physical activity.