Two studies have confirmed that regular vigorous exercise benefits postmenopausal women just like younger women.
The results were based on the studies of endurance training in 50-something women.
"There is some good news here for older women in the population, in that they respond much like younger women do to training. The results are very encouraging for exercise without weight loss as an effective means for increasing vigour and controlling risk factors for chronic diseases in older women," said study leader and exercise physiologist George Brooks, UC Berkeley professor of integrative biology.
"There have been very few studies looking at postmenopausal women, who are different because of decreased estrogen, decreased lean body mass and decreased aerobic capacity. Yet, despite changes in hormones and changes in body composition, postmenopausal women can make significant changes in their cardiovascular fitness without going on extreme diets," said Dr. Zinta Zarins.
Although the endurance training involved cycling on an exercise bike for an hour, five days a week, at 65 percent of maximum lung capacity, the researchers noted that even less strenuous aerobic exercise would likely produce some benefit.
"Most people don't exercise at this level, but some exercise is better than none at all," said Zarins.
He noted that 60 minutes of jogging on a treadmill or swimming should be as effective as an hour on a stationary bike.
Brooks noted that a woman's metabolism changes as her hormone levels change after menopause, affecting glucose clearance from the blood, for example.
The study was conducted to determine whether women achieve the same benefits from endurance training after menopause as they did before.
"We've done lots of studies on the effects of activity and training on metabolism in younger men and women, but this is the first in an older population," said Brooks.
The researchers found that participants increased their body's capacity to consume and use oxygen - their VO2 max - by an average of 16 percent and dropped their resting heart rates by an average of 4 beats per minute.
Brooks said that after the age of 30, people lose the capacity to consume and use oxygen at about 1 percent per year.
"So, in effect, the women in our study had the cardiovascular and metabolic capabilities of women 16 years younger," he said.
At the end of the study, the women's blood pressure during exercise had dropped by 8 millimetres of mercury, while their heart rates were 19 beats per minute less when performing at the same intensity as early in the study.
Besides, the women decreased their carbohydrate burning during exercise and increased their fat burning by about 10 percent.
Women in the study maintained their body weight as a way to balance energy input and expenditures.
A second paper showed that the women's use of blood glucose and their insulin levels during exercise showed similarities to those of younger women.
The first study was published in the latest issue of the journal Metabolism - Clinical and Experimental, while the second study was published in an earlier issue of the Journal of Applied Physiology.