Looking for a magic elixir for health? There’s more evidence exercise may be it, improving thinking skills in older adults and protecting against heart damage in obese people, two separate studies published Monday show.
“Exercise has many, many benefits. ... I don’t know that we fully understand why it has so many beneficial effects for so many organs and systems,” Dr. Roberta Florido, a cardiology fellow at the Johns Hopkins Hospital, told TODAY, as she listed some of the other known benefits, including improving depression, lowering blood pressure and strengthening muscles.
“We should do a better job of telling our patients to exercise,” she added.
In the first paper, published in the British Journal of Sports Medicine, researchers at the University of Canberra in Australia analyzed 39 previous studies looking into the effect of exercise on thinking skills in people over 50. That included things like memory, alertness and the ability to quickly process information.
They found physical activity improved all of those skills regardless of a person’s cognitive status.
The key was 45-60 minutes of moderate to vigorous exercise per session “on as many days of the week as feasible.” A combination of both aerobic exercise and resistance training worked best.
Each type of exercise seemed to have different effects on the factors responsible for the growth of new neurons and blood vessels in the brain, said co-author Joe Northey, a PhD student at the University of Canberra Research Institute for Sport and Exercise.
Tai chi was also helpful, though more evidence is needed to confirm this effect, the researchers note.
"Age is a risk factor no one can avoid when it comes to cognitive decline," Northey said. "As our study shows, undertaking just a few days of moderate intensity aerobic and resistance training during the week is a simple and effective way to improve the way your brain functions."
The second study, published in Journal of the American College of Cardiology: Heart Failure, found exercise was particularly beneficial for obese people, protecting them against heart damage. When researchers studied more than 9,000 people without heart disease, those who were heavy and exercised the least were most likely to have high levels of a heart damage marker. But that link diminished in obese people who stayed active.
Florido, a co-author of the paper, said she and her colleagues didn’t have a good explanation for exactly how it works, but speculated that staying active helps the heart deal with certain stressors.
“It may be that exercise increases the tolerance of the heart to the bad substances that we accumulate in our body with obesity,” she said.
Physical activity can also lower the risk of heart damage in middle-aged and older adults, the researchers found.
Still, only 43 percent of people in the study engaged in the amount of exercise recommended by the American Heart Association, a statistic Florido called “awful.”
The consequences have a huge financial impact: about $117 billion in healthcare costs are associated with inadequate physical activity, and people who are sedentary pay $1,437 more per year in healthcare costs than those who are physically active, notes a companion editorial to the study.
What you should know:
Start exercising now: People who consistently exercise get the most benefit, but for coronary heart disease, you’ll have some protection even if you start later in life, Florido said. Obese people should “absolutely” exercise, she added.
Check with your doctor before you start any new workout routine, of course.
Get the recommended amount of exercise:
• At least 30 minutes of moderate-intensity aerobic activity at least five days per week, for a total of 150 minutes
• At least 25 minutes of vigorous aerobic activity at least 3 days per week for a total of 75 minutes
• Muscle-strengthening activity at least two days per week.
“People usually think of exercise as a goal to lose weight. What we’re finding more and more is that even if you don’t lose weight, exercising has several benefits,” Florido noted.