Background/Purpose: The Walk4Life Model MVP is the only swing-arm pedometer intended to estimate moderate-to-vigorous physical activity (MVPA). This study examined the validity of this claim.
Method: Participants (27 male, 38 female; M age = 20.17 years, SD = 4.08) wore the pedometer during treadmill walking tests and a 30 minute game-play session. Pedometers were calibrated during a five minute treadmill walking bout to determine target treadmill speed and steps-per-minute threshold. Manual step counts were used as reliability checks and Polar model T31 heart rate monitors to monitor heart rate. Two, four minute bouts (one slower and one faster than target speed) were conducted to estimate MVPA. Pedometer estimates from the game-play session were compared to estimates from the System for Observing Fitness Instruction Time (SOFIT) .
Analysis/Results: A dependent t-test indicated that manually counted steps (M= 121.56, SD= 10.27) did not significantly differ (p= .30) from pedometer recorded steps (M= 121.80, SD= 10.62). A 2 (gender) x 2 (treadmill test) repeated measures ANCOVA with BMI as a covariate did not indicated a significant effect for BMI (p= .664) or gender (p= .721). A 2 (gender) x 2 (estimator) repeated measures ANCOVA with BMI as a covariate yielded a significant effect for gender (p= .020) and for BMI (p= .041).
Conclusions: The pedometers reliably and accurately measured steps. During the treadmill test, the pedometers overestimated MVPA at slower speeds (M AE= -26.55) and underestimate MVPA at higher speeds (M AE= 23.53). BMI was a factor in estimating MVPA during field testing.