Elderly women can increase muscle strength as much as young women can, a new study from the University of New Hampshire (UNH) finds. The study indicates decline in muscle function is less a natural part of the aging process than due to a decline in physical activity.
The research compared strength gains of inactive elderly women and inactive young women after both groups participated in an 8-week training regime. Yet while the two groups increased similar percentages of strength, the older group was far less effective in increasing power, which is more closely related to preventing falls.
“Power is more important than strength for recovery from loss of balance or walking ability,” Dain LaRoche, assistant professor of exercise science at UNH and the lead author of the study, said.
Preventing falls, which occur in 40% of people over 65 and are the top reason for injury-related emergency room visits, is the driving force behind LaRoche’s research agenda.
LaRoche compared the initial strength of 25 young (ages 18 to 33) and 24 older (ages 65 to 84) inactive women then had both groups participate in resistance training on a machine that targeted knee extensor muscles, which are critical for walking, stair-climbing, or rising from a chair.
After 8 weeks of training, the older group not only increased their strength by the same percentage as the younger group, they achieved gained strength similar to a control group of young inactive women. But the older group’s ability to increase power – force over time – was significantly less than the younger group’s; the elderly women saw only a 10% increase in power versus the younger women’s 50% increase.
“It’s somewhat troublesome that these older individuals had a reduced capacity to increase performance that’s so closely associated with falls,” LaRoche said.
It seems that the key to muscle power in the elderly is to maintain it over the lifespan rather than try to develop it later in life, he says.
Acknowledging that the type or frequency (6 sets, 3 times per week) of his training protocol may have affected the older group’s ability to make gains in power, LaRoche is continuing to research older women’s capacity to develop muscle power.
Of those 40% of elderly people who will fall, research has shown that 20% to 30% suffer injuries that reduce mobility, independence and longevity. Health care cost of a fall injury totals nearly $20,000, and following a hip fracture, life expectancy is just two years.
