Intensity versus duration of physical activity: implications for the metabolic syndrome. A prospective cohort study

OBJECTIVES: To explore the relative importance of leisure time physical activity (LTPA), walking and jogging on risk of developing the metabolic syndrome (MS). DESIGN: A prospective cohort study. SETTING: The Copenhagen City Heart Study. PARTICIPANTS: 10 135 men and women aged 21–98 years who attended an initial examination in 1991–1994 and were re-examined after 10 years. OUTCOME MEASURES: The association of LTPA, jogging, walking speed and walking volume with MS at baseline and at 10-year follow-up was investigated by multiple logistic regression analyses. RESULTS: Baseline prevalence of MS was 20.7% in women and 27.3% in men. In both women and men, MS prevalence was associated with lower LTPA and walking speed and was lower in joggers compared to non-joggers. In subjects free of MS at baseline, 15.4% had developed MS at 10-year follow-up. Risk of developing MS was reduced in subjects with moderate or high LTPA, higher walking speed and in joggers whereas a higher volume of walking was not associated with reduced risk. After multiple adjustment, odds ratio (OR) of developing MS in moderate/high LTPA was 0.71 (95% CI 0.50 to 1.01), fast walking speed 0.51 (0.33 to 0.80) and joggers 0.60 (0.37 to 0.95) and walking >1 h daily 1.22 (0.91 to 1.65). CONCLUSIONS: Our results confirm the role of physical activity in reducing MS risk and suggest that intensity more than volume of physical activity is important.