AIM: Physical activity (PA) confers some protection against development of heart failure (HF) but little is known of the role of intensity and duration of exercise.

METHODS AND RESULTS: In a prospective cohort study of men and women free of previous MI, stroke or HF with one or more examinations in 1976-2003, we studied the association between updated self-assessed leisure-time PA, speed and duration of walking and subsequent hospitalization or death from HF. Light and moderate/high level of leisure-time PA and brisk walking were associated with reduced risk of HF in both genders whereas no consistent association with duration of walking was seen. In 18,209 subjects age 20-80 with 1580 cases of HF, using the lowest activity level as reference, the confounder-adjusted hazard ratios (HR) for light and moderate/high leisure-time physical activity were 0.75 (0.66-0.86) and 0.80 (0.69-0.93), respectively. In 9,937 subjects with information on walking available and 542 cases of HF, moderate and high walking speed were associated with adjusted HRs of 0.53 (0.43-0.66) and 0.30 (0.21-0.44), respectively, and daily walking of ½-1 hrs, 1-2 and >2 hrs with HR of 0.80 (0.61-1.06), 0.82 (0.62-1.06), and 0.96 (0.73-1.27), respectively. Results were similar for both genders and remained robust after exclusion of HF related to coronary heart disease and after a series of sensitivity analyses.

CONCLUSIONS: Speed rather than duration of walking was associated with reduced risk of HF. Walking is the most wide-spread PA and public health measures to curb the increase in HF may benefit from this information.