Limitations of cadence-based walking for assessing bouts of moderate-to vigorous-intensity physical activity under free-living conditions

The purpose of the present investigation was to examine the relationship between the accumulation of 1000 steps in 10 minutes (1K) and 3000 steps in 30 minutes (3K) with the amount and intensity of daily physical activity. Thirty-three adults (16 males and 17 females, 53 +/- 19 years) wore an accelerometer (Lifecorder) for seven consecutive days in order to determine the number of steps and the time spent in physical activity at light intensity (LPA), moderate intensity (MPA), vigorous intensity (VPA) and moderate to vigorous intensity (MVPA). Furthermore, based on the minute-by-minute stepping rate, the number, intensity and duration of walking bouts (1K and 3K) were evaluated. The daily number of steps, LPA, MPA and VPA were significantly higher on the days with 1K or 3K compared with that observed on the days without 1K or 3K (P < 0.05). The duration of 1K was not found to be correlated with an MVPA >10 minutes. An MVPA >10 minutes was less than 2 min . day(-1) on the days with 1K or 3K. Therefore, it is doubtful that the concept of cadence is an alternative indicator for the commonly used definition of MVPA. It remains unclear whether participation in 1K and 3K guarantees that an individual will meet the current MVPA guidelines.