Study on the Characteristics of ActiGraph Accelerometer Vector Activity Counts and the Correlation between the Parameters and Energy Expenditure during Walking and Running

Objective:To investigate the characteristic of GT3X+ accelerometer's basic parameters and the correlation between the parameters and energy expenditure during treadmill walking and running in adult men and women.Methods:A total of 51participants (25 men, 26 women, ages at 20~30yrs) performed five 5-min treadmill walking/running tests (3.0km/h, 4.5km/h, 4.5km/h at 10% grade, 6km/h, 7.5km/h) .Results:1) In both subject groups, along with the increase of speed, VM, VT activity counts gradually increased.AP activity counts increased gradually from 3km/h to 6km/h, but decreased significantly in 7.5km/h.2) Unlike other parameters, ML activity counts in 4.5km/h plus 10% grade walking were greater than 6km/h walking.3) VT activity counts were greater than HV In all speed except3km/h (P<0.01) .4) AP activity counts were greater in female than in male, but there was no significant difference about VM, VT, ML (except 3km/h) between the two subject groups.5) The correlation of VM and other parameters from high to low were VT, HV, ML, AP, and VM was highly correlated with VT (r=0.983, P<0.01) .6) EE (k4b2) were highly correlated with VT and VM, but lowly with AP and ML.Conclusions:During walking and running on the treadmill (except 3.0km/h) , VT activity count was the maximum in the three accelerate vector.From walking to running, the largest increase occurred in VT, but AP decreased.ML was one of the main parameters to induce whether the slope existed on the treadmill.In a certain speed range, VT and VM were both the best argument for the calculation of energy expenditure on the treadmill, but VT could meet the need to predict energy expenditure.