Source
Dept of Exercise and Wellness, Arizona State University, Mesa 85212, USA.
Abstract
PURPOSE:
(a) To establish pedometer steps/min intensity categories (i.e., light, moderate, hard, very hard) for adults under controlled conditions, and (b) use these cut-points to ascertain the number of steps expected in 30 minutes of moderate intensity activity.
METHODS:
25 men and 25 women, ages 18-39 years, performed 6-min exercise bouts at 3 treadmill speeds (4.8, 6.4, and 9.7 km/hr). Yamax SW-200 pedometers indicated steps, and steady-state VO2 was recorded. METs were calculated by dividing steady-state VO2 by 3.5 ml x kg(-1) x min(-1). Linear regression was used to quantify the relationships between steps/min and METs across all speeds. Ten participants (5 M, 5 F) were randomly selected from the original 50 and constituted a holdout sample for cross-validation purposes (i.e, comparing actual and predicted METs; paired t-test).
RESULTS:
The regression equation for males was: METs = -7.065 + (0.105 x steps/min) r2 = 0.803. For females it was: METs = -8.805 + (0.110 x steps/min) r2 = 0.830. Cross-validation was confirmed.
CONCLUSIONS:
Pedometer cut-points corresponding to minimal moderate intensity walking were 96 steps/min in men and 107 steps/min in women, or roughly 100 steps/min for both. This translates to approximately 3,000 steps in 30 min of moderate-intensity ambulatory activity for both genders.