Physical activity in Brazilian adultsABSTRACTPurpose: To measure the prevalence of low physical activity, and variables associated with it, in an adult population in southern Brazil. Methods: Population-based cross-sectional study covering a multiple-stage sample of 3,182 subjects aged 20 years or more. Physical activity was assessed through the short version of the International Physical Activity Questionnaire (IPAQ), using home interviews with last week recall. The questionnaire covers leisure, occupation, transportation and housework activities. Low physical activity was defined as fewer than 150 minutes per week spent in moderate or vigorous physical activities. The time spent in vigorous activities was multiplied by two. Results: The prevalence of low physical activity was 41.1%. Low physical activity was positively associated with age and socioeconomic level, and inversely associated with self-reported health status. Those without education, with white skin color and women who live alone rather than with a partner were significantly more likely to have low physical activity. Conclusion: The prevalence of low physical activity in Brazilian adults is high, even though lower than reported in studies of leisure-time activity alone in other populations. Studies in developing countries may be seriously biased if activities during labor, transportation and housework are not assessed.Key-words: 1.Exercise 2.Epidemiology 3.Developing countries 4.Cross-sectional studies 5.Sedentarism

ARTIGO 2“COMPARISON BETWEEN SHORT AND FULL-LENGTH INTERNATIONAL PHYSICAL ACTIVITY QUESTIONNAIRES (IPAQ)�

PURPOSES: TO COMPARE THE SHORT AND FULL-LENGTH VERSIONS OF THE INTERNATIONAL PHYSICAL ACTIVITY QUESTIONNAIRE (IPAQ) FOR DETECTING LOW PHYSICAL ACTIVITY LEVELS.METHODS: BOTH VERSIONS WERE APPLIED TO 186 SUBJECTS IN A MIDDLE CLASS AREA OF THE CITY OF PELOTAS, BRAZIL. HALF THE SUBJECTS ANSWERED THE LONG AND THEN THE SHORT VERSION, AND THE OTHER HALF ANSWERED THEM IN THE OPPOSITE ORDER. LOW PHYSICAL ACTIVITY WAS DEFINED AS BELOW 150 MINUTES OF ACTIVITY OF AT LEAST MODERATE INTENSITY PER WEEK. RESULTS: TREATING THE LONG VERSION AS THE REFERENCE METHOD, THE SENSITIVITY OF THE SHORT IPAQ FOR DETECTING LOW PHYSICAL ACTIVITY WAS 87% AND ITS SPECIFICITY 75%. THE PREVALENCE OF LOW PHYSICAL ACTIVITY WAS 50% HIGHER ACCORDING TO THE SHORT IPAQ. WITH THE SHORT VERSION, SUBJECTS UNDERREPORTED HOUSEHOLD, OCCUPATIONAL AND LEISURE ACTIVITIES. A FORMULA WAS CALCULATED TO CORRECT VALUES OBTAINED WITH THE SHORT VERSION FOR ITS MEAN BIAS. CONCLUSION: THE SHORT AND THE LONG IPAQ VERSIONS PRODUCE SUBSTANTIALLY DIFFERENT RESULTS, HOWEVER THE MEAN BIAS CAN BE CORRECTED. FURTHER WORK IS REQUIRED TO VALIDATE THE LONG VERSION AGAINST ALTERNATIVE METHODS SUCH AS ACTOMETERS TO CONFIRM THAT IT PROVIDES VALID MEASURES OF PHYSICAL ACTIVITY.

KEY WORDS: EPIDEMIOLOGY, PHYSICAL ACTIVITY, VALIDATION STUDIES, QUESTIONNAIRES.