Training did benefit the younger subjects, too, but rather than becoming more efficient, the younger participants boosted their peak oxygen consumption.
The authors wrote that since the older participants were able to erase many of the starting differences in exercise factors, some of the decline typically seen with aging may not be inevitable; rather it may reflect a lack of fitness, which can be addressed with training.
Dr. Levy said their results leave some question unanswered.
"It is unknown the duration, intensity, and mode of exercise training necessary to improve efficiency in the older subjects. Will simple walking for two to four weeks be adequate or is more vigorous exercise necessary?" he noted.
"What was new and unexpected in our study was the disproportionately greater response to training in the elderly subjects," the authors wrote.
Edward G. Lakatta, M.D., from the National Institute on Aging Intramural Research Program, Gerontology Research Center in Baltimore, Maryland, who wrote an editorial in the journal with Paul D. Chantler, Ph.D., pointed out that this study looked at oxygen consumption and exercise efficiency in a way most studies have not. The results offered both good and bad news about aging.
"In summary, the bad news conveyed to us by Woo et al. is that metabolic debts associated with the performance of dynamic exercise increase with aging. These debts, paid during recovery from exercise are likely attributable to an inability of the older body to adapt to the energy requirements of exercise," they wrote.
But there was also good news in the results.
"A relatively low level of aerobic training for six months was able to improve exercise efficiency, reduce o
'"/>
Contact: Amy Murphy
amurphy@acc.org
301-581-3476
American College of Cardiology
7-Mar-2006