Pedometer steps-per-minute, moderate intensity, and individual differences in 12- to 14-year-old youth

Background:Researchers have noted both the utility and limitations of using pedometers to measure physical activity (PA). While these unobtrusive devices are widely accepted for their ability to measure accumulated PA, they have been criticized for their inability to measure exercise intensity. However, recent steps-per-minute (SPM) research provides reasonably accurate measures of intensity allowing users to assess time spent at recommended PA levels. Therefore, the purpose of this study was to determine the SPM taken that are associated with moderate physical activity in 12- to 14-year-old youth.Methods:Ninety-three participants (49 boys and 44 girls; ages 12 to 14) walked on a treadmill for 3 minutes at each of 4 different speeds while wearing a pedometer and a heart rate monitor.Results:On average boys and girls reached their moderate activity intensity threshold at 122 SPM and 102 SPM, respectively. However, individual differences must be taken into account when determining appropriate SPM intensities for youth.Conclusions:The impact of individual differences underscores the need to address SPM for moderate intensity individually rather than with a single guideline for everyone at this age.