Most Americans still do not work out enough

First the good news: More adult Americans are getting in shape.

Now the cold water: Most are still slacking off.

Not surprisingly, both trends can be seen distinctly among aging baby boomers, a generation convinced of its indestructibility but prone to ignoring well-meaning advice — including the recommended amount of exercise they should get every week.

The most recent federal health data show a steady climb since 2007 in the number of US adults meeting weekly workout goals, which include a minimum of 150 minutes of moderate aerobic activity, or 75 minutes of vigorous activity. An estimated 49.7 percent of those interviewed met or exceeded the guidelines in the first six months of last year, the latest period sampled. That was the agency's highest recorded level of fitness ever.

However, that still means more than half of adults are not doing enough aerobic exercises, and many more are not doing the suggested amount of strength training, such as weightlifting. Just 20.7 percent of Americans between the ages of 25 and 64 worked out enough each week to meet the recommended levels for both strength and aerobic exercise.

Even so health professionals said more Americans now understand the benefits of exercise, diet, and healthy living, that more people from all backgrounds are embracing fitness goals than ever before. The goals for individuals vary widely.

"If you're the average American who doesn't get enough exercise, you're not going to run a marathon tomorrow," said Amy O'Neil, director of wellness program development for Blue Cross Blue Shield of Massachusetts, the state's largest health insurance company. "But you have to exercise a certain amount at a certain intensity almost every day of the week."

For younger people, the goal may be to look or feel better. Older people, meanwhile, work out to remain independent as they age.

Strength training, to cite one regimen, can prevent the loss of bone density in older people, especially postmenopausal women who may be more comfortable doing aerobics and other exercises than lifting weights.

"Purely aerobic training is great," said Ryan P. Sherman, a certified health and wellness coach at Massachusetts General Hospital in Boston. "But if you're not doing strength training as well, it will put you at greater risk for orthopedic injuries. If you can stabilize those joints through muscle, whether it's a knee or a shoulder, you can better absorb that pounding."

In addition to cardiorespiratory activity and strength training, fitness coaches counsel avoiding tobacco, reducing stress, improving sleeping habits, and increasing flexibility through stretching or yoga. New research shows stretching is more important after running, walking, or other aerobic activity as opposed to beforehand, according to Sherman.

Sherman, a registered clinical exercise physiologist, works at Mass. General's experimental Ambulatory Practice of the Future, which now treats mostly hospital employees and their families. He hopes the wellness and goal-oriented preventive health concepts being pioneered at his practice and elsewhere will spread across the country in coming years.

"We're trying to change the way we look at things in health care," he said. "I always tell patients when they come in, 'You're going to drive this. I'm just going to be the GPS that helps you get to your goal.' As humans, we don't like to be told what to do. It has to come from the patient. For some, the goal is to run a marathon. For others, it's losing 60 pounds."

Both Sherman and O'Neil said many baby boomers — particularly those with grown children and financial security — recommit to exercise and are often more active than their younger working colleagues.

Some, however, push themselves too hard, they said, turning up in emergency rooms with stress fractures, Achilles tendon ruptures, and other overuse injuries.

O'Neil, a trained exercise physiologist, works with Massachusetts employers to design fitness and wellness programs, focusing on "health behavior changes," offering rewards, and introducing devices such as pedometers and accelerometers, which track employees' activity.

"All of these things, the gadgets and incentives, are to motivate people," O'Neil said. "When you're doing a worksite wellness program, one size doesn't fit all. People are really becoming aware that wellness is important. And they're understanding that unhealthy habits have financial consequences. But not everyone's doing it and some say it's not fun anymore."

Getting employees to buy-in up front — and letting employers and individuals design their own wellness programs and goals — is the approach most likely to succeed, she said.

"The awareness is there," O'Neil said. "But the question is how you get people to act on it. If it was just about education, everyone would be healthier because the information is out there."

Sherman said it's important to give patients positive reinforcement.

"People come in and say, 'I'm 60 years old, I'm 50 pounds overweight. Is it too late?' " he said. "The answer is no. They can get back to the weight they had in their 20s. I see it all the time. You can't be 20 again, but you can be fit at 60."

Robert Weisman can be reached at weisman@globe.com. Follow him on Twitter @GlobeRobW.