1School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, Scotland, UNITED KINGDOM; and 2Social and Public Health Sciences Unit, Medical Research Council, Glasgow, Scotland, UNITED KINGDOM.
Med Sci Sports Exerc. 2013 Oct;45(10):1995-2001. doi: 10.1249/MSS.0b013e3182955780.
The term cadence has been used interchangeably to describe both the rate of stepping and the number of steps in a minute epoch. This is only strictly true if walking is continuous within that epoch. This study directly compared these two outcomes in minute epochs of data from free-living adults to assess the scale of any difference between them.
A convenience sample of healthy adults wore an activPAL activity monitor for 7 d. The event record output of the activPAL, providing the start time and duration of each stride to the nearest 0.1 s, was used to calculate step accumulation (number of steps), duration of walking, and cadence (number of steps/duration of walking) for each minute of measurement.
Data from 117 individuals (78 females; mean age, 46 ± 16 yr; mean body mass index, 24.9 ± 3.7 kg·m-2) were analyzed. Twenty-one percent of minutes (n = 310d-1) contained walking. The distribution (most minutes fewer than 40 steps per minute) and mean (34 ± 9 steps per minute) of step accumulation were very different from that of cadence (most minutes between 60 and 100 steps per minute; mean, 76 ± 6 steps per minute). Only 12% of minutes with stepping were walked continuously, whereas 69% of minutes with stepping contained less than 30 s of walking. This is key to the difference between step accumulation and cadence, and means that cadence cannot be reconstructed from step accumulation without also knowing the duration that was walked.
Step accumulation, the number of steps in a fixed period, and cadence, the rate of stepping while walking, are not interchangeable outcome measures. It is vitally important that unambiguous terminology is used to describe the rate of stepping so that the outcomes of studies can be correctly interpreted.
“步频”一词曾被交替用于描述每分钟的步数和步伐周期。只有在步伐周期内连续行走时，这才是严格正确的。本研究通过比较自由生活成年人分钟数据的这两个结果，直接评估了它们之间差异的幅度，从而评估了它们之间差异的幅度。
选择了一个健康成年人的便利样本，让他们佩戴 activPAL 活动监测器 7 天。activPAL 的事件记录输出提供了每个步伐的起始时间和持续时间，精确到 0.1 秒，用于计算每分钟测量的步数积累（步数）、行走持续时间和步频（步数/行走持续时间）。
共分析了 117 人的数据（78 名女性；平均年龄 46±16 岁；平均体重指数 24.9±3.7kg·m-2）。21%的分钟（n=310d-1）包含行走。步数积累的分布（大多数分钟的步数少于 40 步/分钟）和平均值（34±9 步/分钟）与步频（大多数分钟在 60 到 100 步/分钟之间；平均值，76±6 步/分钟）非常不同。只有 12%的有步幅的分钟是连续行走的，而 69%的有步幅的分钟中行走时间不到 30 秒。这是步数积累和步频之间差异的关键，这意味着如果不知道行走的持续时间，就不能从步数积累中重建步频。
步数积累，即固定时间段内的步数，和步频，即行走时的步伐率，不是可互换的结果测量指标。使用明确的术语来描述步伐率至关重要，以便正确解释研究结果。
