Physical activity (PA) is known to contribute to improvements in cardiometabolic risk (CMR) factors, but doses of PA necessary to achieve healthy CMR profiles are not well understood.
PURPOSE: To quantify the relationships among various expressions of PA and CMR profiles in adults. METHODS: Between 6:00 and 9:00 am, participants arrived at the laboratory having fasted for at least 10 hours. Height and body mass were measured, and 4-compartment body composition (percent body fat [%BF], fat mass [FM] and fat-free mass [FFM]) was determined using data derived from bioelectric impedance analysis and dual energy X-ray absorptiometry. Resting heart rate, systolic and diastolic blood pressure were measured, and mean arterial pressure (MAP) was calculated. Blood samples were collected and plasma lipids (total, HDL, and LDL cholesterol [TOT-C, HDL-C, LDL-C]), triglycerides (TG), insulin (INS), and glucose (GLU) were measured. Quantitative insulin sensitivity check index (QUICKI) and TOT-C: HDL-C ratio were calculated. Accelerometers were then provided and were worn for 21-28 days. Thereafter, associations between markers of PA and CMR factors were analyzed. RESULTS: A total of 21 females (age = 31.3 ± 4.1 years, weight = 80.3 ± 22.7 kg, height = 167.4 ± 8.0 cm, BMI = 28.6 ± 7.5 kg·m-2) and 20 males (age = 32.2 ± 5.4 years, weight = 93.7 ± 19.1 kg, height = 180.4 ± 7.2 cm, BMI = 28.8 ± 5.3 kg·m-2) participated. STEPS expressed in absolute terms (STEPS·day-1) was not associated with any CMR factors. STEPS expressed relative to body mass (STEPS·kg-1·day-1) was correlated with %BF (-0.44), MAP (-0.48), HDL-C (0.41), TG (-0.33), TOT-C:HDL-C ratio (-0.36), INS (-0.56), and QUICKI (0.59). STEPS relative to FM (STEPS·kgFM-1·day-1) was correlated with %BF (-0.72), MAP (-0.32), HDL-C (0.38), TOT-C:HDL-C ratio (-0.42), GLU (-0.39), INS (-0.37), and QUICKI (0.47). STEPS expressed relative to FFM (STEPS·kgFFM-1·day-1) was correlated with INS (-0.32). Power regression analysis showed that STEPS·kgFM-1·day-1 was the best predictor of %BF (r2 = 0.85), QUICKI (r2 = 0.47) and TOT-C:HDL-C ratio (r2 = 0.29). CONCLUSIONS: These findings suggest that STEPS expressed relative to FM are strongly associated with CMR factors, and that prescribing STEPS relative to FM may be efficacious for improving CMR profiles in adults.
Collapse
