Faculty of Kinesiology, Department of General and Applied Kinesiology, University of Zagreb, 10000 Zagreb, Croatia.
Faculty of Sports Studies, Masaryk University, 60177 Brno, Czech Republic.
Int J Environ Res Public Health. 2020 Jan 16;17(2):593. doi: 10.3390/ijerph17020593.
Although it has been well-documented that older adults spend a significant amount of time being sedentary and have slower gait velocity, little is known of how physical fitness mediates the association between them. The main purpose of this study was to explore whether objectively measured physical fitness mediates the association between domain-specific and total sedentary behavior and gait velocity. We recruited 120 older adults aged ≥ 60 years. Sedentary behavior was assessed by the Measure of Older Adults' Sedentary Time questionnaire. We used a Zebris pressure platform to assess gait velocity. To assess the level of overall physical fitness, we summed the -scores of seven tests: (1) waist circumference, (2) chair stand in 30 s, (3) arm curl in 30 s, (4) 2-min step test, (5) chair sit-and-reach test, (6) back scratch test, and (7) 8-foot up-and-go test. Overall physical fitness was obtained by summing up all physical test -scores. Gait velocity was significantly associated with all domain-specific and total sedentary behavior ( = -0.04 to -0.35, < 0.05). Overall physical fitness was significantly associated with all domain-specific and total sedentary behavior ( = -0.21 to -1.24, < 0.001) and gait velocity ( = 0.23 to 0.24, < 0.001). When physical fitness was put as the mediator, significant direct effects between sedentary behavior and gait velocity disappeared. Results indicate that physical fitness fully mediates the association between sedentary behavior and gait velocity in older adults.
虽然已有大量文献证实老年人久坐时间长且步速较慢，但对于身体机能如何调节两者之间的关系却知之甚少。本研究的主要目的是探讨身体机能是否在特定领域和总久坐行为与步速之间的关联中起中介作用。我们招募了 120 名年龄≥60 岁的老年人。通过“老年人久坐时间测量问卷”评估久坐行为。我们使用 Zebris 压力平台评估步速。为评估整体身体机能水平，我们将 7 项测试的 -分数相加：（1）腰围，（2）30 秒内坐站，（3）30 秒内手臂弯曲，（4）2 分钟踏步测试，（5）坐-立前伸测试，（6）后背挠痒测试，和（7）8 英尺起走测试。整体身体机能由所有身体测试的 -分数相加得出。步速与所有特定领域和总久坐行为均显著相关（ = -0.04 至 -0.35， < 0.05）。整体身体机能与所有特定领域和总久坐行为均显著相关（ = -0.21 至 -1.24， < 0.001）和步速（ = 0.23 至 0.24， < 0.001）。当身体机能作为中介时，久坐行为与步速之间的直接效应显著消失。结果表明，身体机能完全中介了老年人久坐行为与步速之间的关系。
