Are there really many runners out there? Is the proportion of runners increasing over time? A population-based 12-year repeated cross-sectional study with 625,460 Brazilians.

Objectives: To investigate the proportion of individuals who practice running, its temporal trend, and to describe the runners' characteristics.

Design: Population-based repeated cross-sectional study.

Methods: The data from the Protective and Risk Factors for Chronic Diseases by Telephone Survey (Vigitel) from Brazil were used. Telephone interviews were conducted with adults from the Brazilian capitals (27 cities) between 2006-2017. The interviewer read the questions and recorded the participants' responses immediately in a questionnaire. Data analyses were conducted using a Bayesian approach.

Results: The Vigitel database consisted of 625,460 Brazilian participants composed of 295,681 exercisers and within them 15,529 runners. The mean yearly proportion of runners was about 2.45% (95% Bayesian credible interval [CrI] 1.93 to 3.11) and 5.32% (95%CrI 4.29 to 6.54) in the entire study population and within exercisers, respectively. The absolute increase in the proportion of runners per year over the 12-year period was 0.13% and 0.17% in the entire study population and within exercisers, respectively. Runners were more likely to be younger, men, within normal body mass index, highly educated, moderate alcohol drinkers, non-smokers, less exposed to TV, living near physical activity/sports facilities and less exposed to health conditions such as arterial hypertension, diabetes and dyslipidaemia.

Conclusion: There was a 95% probability that the yearly proportion of runners lies between 1.93% and 3.11% in the population of the 27 Brazilian capitals, and between 4.29% and 6.54% within exercisers. There has been an increase in the proportion of runners over time. Runners were associated with healthier characteristics compared to non-runners and non-exercisers.