Sporadic and bouted physical activity and the metabolic syndrome in adults

Physical activity guidelines recommend that adults accumulate at least 150 min of moderate-to-vigorous physical activity (MVPA) per week in bouts of at least 10 min. However, sporadic MVPA contributes significantly to total physical activity and may also affect health. The study objective was to determine, within adults age 18 to 64 yr, whether MVPA accumulated in bouts is more strongly associated with metabolic syndrome (MetS) than an equivalent volume of MVPA accumulated sporadically.

The study sample included 1119 adults age 18 to 64 yr from the 2007-2009 Canadian Health Measures Survey, a nationally representative cross-sectional study. The energy expenditure from bouted (at least 10 consecutive minutes) and sporadic (<10 consecutive minutes) MVPA was measured for 7 d using Actical accelerometers. The presence of MetS was determined using established criteria. Associations were examined using logistic regression and controlled for covariates (age, sex, education, diet, and smoking).

After adjusting for the covariates and each other, bouted and sporadic MVPA were independently associated with the MetS. For each additional MET-hour per week of bouted MVPA, the relative odds of the MetS decreased by 9% (95% confidence interval, 3%-14%). For each additional MET-hour per week of sporadic MVPA, the relative odds of the MetS decreased by 11% (5%-16%). Overlapping confidence interval indicates no difference in the effect estimates for bouted and sporadic MVPA. Secondary analyses revealed that small bursts of sporadic MVPA (1-3 min) were meaningful when predicting the MetS.

Within this representative sample of Canadian adults, sporadic MVPA was associated with the MetS to a similar order of magnitude as an equivalent volume of bouted MVPA.