FRIDAY, Sept. 2 (HealthDay News) -- It would be hard, these days, not to have heard that regular exercise can provide innumerable health benefits and help people enjoy longer, happier and more active lives.

What's more, fitness experts have determined that people don't have to work themselves to exhaustion or set aside large chunks of time to reap the benefits.

Nonetheless, large numbers of people are either getting no exercise at all or are getting too little to do themselves any good, health experts say.

So why aren't more people getting off the couch and moving?

A lot of it has to do with time, said Michael R. Bracko, a sports physiologist and director of the Institute for Hockey Research in Calgary, Canada. Not just the amount of time people have, but also the amount of time they think they have.

"In this day and age, with all the stuff we have going on, probably the number one reason is perceived lack of time," Bracko said. "People don't view exercise or physical activity as important enough to schedule it within their day. They can't find the time to work out. They've got kids, they're driving around, they're working, they're commuting."

However, health experts stress that participation in regular physical activity can reap a ream of health benefits.

Physical activity helps the body regulate blood sugar levels and lower blood pressure, reducing the chances of developing diabetes or heart disease, according to the U.S. Centers for Disease Control and Prevention. Studies have shown that physical activity also maintains healthy muscles, bones and joints, and can slow the deteriorating effects of aging.

Further, exercise improves a person's overall mood by prompting the release of hormones that reduce feelings of anxiety and depression, the CDC says. Some research has even found that exercise helps keep the mind sharp, improving memory and potentially helping to ward off dementia in old age.

Despite all this good news about exercise, a 2008 CDC survey revealed that more than a quarter of American adults did not spend any free time doing physical activities such as running, gardening, golfing or walking.

In a more recent survey, just 5 percent of American adults reported engaging in vigorous physical activity, such as running or using cardiovascular exercise equipment, in the previous 24 hours, according to a study published last fall in the American Journal of Preventive Medicine.

Bracko said he believes that not only do many people have busy schedules but that they still "don't understand or appreciate how much physical activity can have a positive impact on their life."

The CDC has set guidelines for the amount of exercise that people at various stages of their lives need to remain healthy:

• Kids 6 to 17 years old should get about an hour of physical activity every day.
• Adults 18 on up should partake in at least 150 minutes of moderate-intensity aerobic activity, such as brisk walking, or 75 minutes of vigorous-intensity aerobic activity, every week. In addition, at least two days a week they should do muscle-strengthening activities that work all the major muscle groups.

Finding the willpower to set aside this time can be very personal, and people may need to do a little soul-searching to figure out what matters most to them, said Barbara Ainsworth, a professor of exercise and wellness at Arizona State University.

"Everybody has different points that get them to be motivated," Ainsworth said. "It's important to find the triggers that resonate for you."

For some people, it's a doctor's report saying that they are headed for chronic disease if they don't shape up, she said. Others want to look better or improve their athletic ability. Some work out for stress relief or enjoy the social setting that group exercise provides.

To fit exercise into daily life, Bracko and Ainsworth suggested:

• Taking a step back and understanding that fitness is as important a priority as other leisure activities, such as television or reading. "We're busy because we choose to do certain things," Ainsworth said. "It's about making different choices."
• Realizing that exercise can be broken into blocks of 10 to 15 minutes that can be fit in throughout the day. Bracko gives the example of soccer moms who take their kid to games. "They don't realize that's a great time to exercise," he said. But for those who do, "instead of standing on the sidelines, they're walking around the field or running intervals or something," he said.
• Recruiting an exercise buddy who will help maintain motivation. "If you make a date with someone to go on a walk, you don't want to disappoint that person," Ainsworth said.

More information

The U.S. Department of Health and Human Services has a guide for adults on becoming active, healthier and happier.

A companion article describes how a joining a gym might help you get up and get moving.