By Chris Klingenberg
The aging-induced increase in energy cost of walking can be slowed in older adults leading to improved mobility, according to new research published in the journal Innovation in Aging.
“One of the factors that we know leads to mobility limitations in older adults is high energy requirement for walking,” said Dawn Mackey, PhD. “As you get older, it takes more and more energy to walk a given distance. If that energy requirement gets high, it becomes very fatiguing and tiring to walk, which leads to people not walking. So we thought that if there was an ability to intervene with exercise to reduce the energy requirement of walking downstream, then that might have some impact on their mobility.”
Mackey, who is one of the study’s authors, is associate professor of Biomedical Physiology and Kinesiology at Simon Fraser University.
The researchers sought to determine whether three different forms of exercise could reduce the energy cost of walking while improving fatigability, endurance, and physical function, as well as physical activity and life-space mobility among older adults with mobility limitation.
The study, “Randomized Controlled Trial of Exercise to Improve Walking Energetics in Older Adults,” recruited 72 community-dwelling older adults (≥ 65 years) who reported mobility limitation. Participants were randomized into three exercise groups: timing and coordination of gait training (motor skills), outdoor aerobic walk training, or stretching and relaxation training (active control group). Participants met in twice weekly 60-minute sessions for 12 weeks. Measures were taken at baseline, 12 weeks, and 24 weeks.
At the end of 12 weeks, the results showed that timing and coordination training, but not aerobic walking training, reduced the energy cost of walking among older adults with mobility limitation, particularly among those with high baseline energy cost; furthermore, reductions in energy cost were sustained following training cessation.
Exercise session attendance was high: 86% for timing and coordination, 81% for aerobic walking, and 90% for stretching and relaxation. At 12 weeks, timing and coordination reduced the mean energy cost of walking by 15% versus stretching and relaxation (p = .008). Among those with high baseline cost, timing and coordination reduced mean energy cost by 20% versus stretching and relaxation (p = .055). Reductions were sustained at 24 weeks. Aerobic walking had no effect on the energy cost of walking at 12 or 24 weeks.
At 12 weeks, there was a trend toward faster gait speed (by 0.1 m/s) in the timing and coordination group versus the stretching and relaxation group (p = .074). Fatigability, physical activity, endurance, physical function, and life-space did not change with timing and coordination or aerobic walking versus stretching and relaxation at 12 or 24 weeks.
“Evidence suggests a combination of aerobic exercise and weight-bearing resistance training along with strength and balance exercises are important to older adults,” Mackey said, particularly as the combination relates to improving their ability to walk well. “What this study adds is some training that is specific to retraining the coordination of stepping patterns, which would be a good addition to those other types of exercises.”
Source: Collins KJ, Schrack JA, Van Swearingen JM, et al. Randomized Controlled Trial of Exercise to Improve Walking Energetics in Older Adults. Cite as: Innovation in Aging, 2018;2(3):igy022