Sustained vs. Shorter Bouts of Physical Activity and Cardiovascular Health

Introduction Physical activity is known to prevent cardiovascular disease (CVD). However, the relative importance of accumulating physical activity in sustained bouts versus shorter bouts in terms of CVD risk is yet to be determined.

Purpose The aim of this study was to investigate the relationship between moderate-to-vigorous physical activity (MVPA), measured in bouts ≥10 minutes and <10 minutes, and CVD risk factors in a nationally representative sample of adults.

Methods A sub-sample of adults ( aged ≥ 16 years) from the 2008 Health Survey for England with valid accelerometry data for at least 1 day (i.e. ≥ 10 hours of wear time) were included in the study (N = 2353). The one minute epoch ActiGraph GT1M accelerometer data was analysed using KineSoft version 3.3.75. Total MVPA, MVPA accumulated in bouts ≥10 minutes (MVPA10+), and MVPA accumulated in bouts <10 minutes (MVPA<10) were calculated (Troiano et al. 2008). MVPA exposures were related to individual CVD risk factors, including measures of adiposity (BMI & waist circumference), blood cholesterol (Total and HDL), systolic and diastolic blood pressure, and HbA1c, using linear regression (controlling for age, sex, and accelerometer wear time). All statistical analyses were conducted using SPSS version 20.

Results The mean age of the participants was 51.6 years, 55% female, with a mean BMI of 27.5 kg/m2. Total MVPA was significantly associated with lower waist circumference and higher high-density lipoprotein (HDL) levels, (P<0.0001). None of the other CVD risk factors were significant. MVPA10+ also showed statistically significant associations with these two CVD risk factors (P <0.001). However, MVPA<10 was not significant for HDL and the significance level for waist circumference dropped to (P<0.003).

Conclusions