Ortega Justus D, Beck Owen N, Roby Jaclyn M, Turney Aria L, Kram Rodger
Department of Kinesiology & Recreation Administration, Humboldt State University, Arcata, California, United States of America.
Department of Kinesiology & Recreation Administration, Humboldt State University, Arcata, California, United States of America; Department of Integrative Physiology, University of Colorado, Boulder, Colorado, United States of America.
PLoS One. 2014 Nov 20;9(11):e113471. doi: 10.1371/journal.pone.0113471. eCollection 2014.
Impaired walking performance is a key predictor of morbidity among older adults. A distinctive characteristic of impaired walking performance among older adults is a greater metabolic cost (worse economy) compared to young adults. However, older adults who consistently run have been shown to retain a similar running economy as young runners. Unfortunately, those running studies did not measure the metabolic cost of walking. Thus, it is unclear if running exercise can prevent the deterioration of walking economy.
To determine if and how regular walking vs. running exercise affects the economy of locomotion in older adults.
15 older adults (69 ± 3 years) who walk ≥ 30 min, 3x/week for exercise, "walkers" and 15 older adults (69 ± 5 years) who run ≥ 30 min, 3x/week, "runners" walked on a force-instrumented treadmill at three speeds (0.75, 1.25, and 1.75 m/s). We determined walking economy using expired gas analysis and walking mechanics via ground reaction forces during the last 2 minutes of each 5 minute trial. We compared walking economy between the two groups and to non-aerobically trained young and older adults from a prior study.
Older runners had a 7-10% better walking economy than older walkers over the range of speeds tested (p = .016) and had walking economy similar to young sedentary adults over a similar range of speeds (p = .237). We found no substantial biomechanical differences between older walkers and runners. In contrast to older runners, older walkers had similar walking economy as older sedentary adults (p = .461) and ∼ 26% worse walking economy than young adults (p<.0001).
Running mitigates the age-related deterioration of walking economy whereas walking for exercise appears to have minimal effect on the age-related deterioration in walking economy.
步行能力受损是老年人发病的关键预测指标。老年人步行能力受损的一个显著特征是与年轻人相比，代谢成本更高（经济性更差）。然而，持续跑步的老年人已被证明能保持与年轻跑步者相似的跑步经济性。不幸的是，那些跑步研究并未测量步行的代谢成本。因此，尚不清楚跑步锻炼是否能预防步行经济性的恶化。
确定定期步行与跑步锻炼是否以及如何影响老年人的运动经济性。
15名每周步行≥30分钟、锻炼频率为每周3次的老年人（69±3岁），即“步行者”，以及15名每周跑步≥30分钟、锻炼频率为每周3次的老年人（69±5岁），即“跑步者”，在测力跑步机上以三种速度（0.75、1.25和1.75米/秒）行走。在每次5分钟试验的最后2分钟，我们通过呼出气体分析确定步行经济性，并通过地面反作用力确定步行力学。我们比较了两组之间的步行经济性，并与先前一项研究中的非有氧运动训练的年轻人和老年人进行了比较。
在测试的速度范围内，老年跑步者的步行经济性比老年步行者好7 - 10%（p = 0.016），并且在相似的速度范围内，其步行经济性与久坐的年轻成年人相似（p = 0.237）。我们发现老年步行者和跑步者之间没有实质性的生物力学差异。与老年跑步者相比，老年步行者的步行经济性与久坐的老年人相似（p = 0.461），并且比年轻人差约26%（p<0.0001）。
跑步可减轻与年龄相关的步行经济性恶化，而步行锻炼似乎对与年龄相关的步行经济性恶化影响极小。
