Exercise

The best-laid resolutions to get fit can quickly crumble with no plan in place and no budget for a personal trainer. Don't worry -- we asked fitness experts to map out monthlong strategies to jump-start running, cycling, swimming and strength-training programs designed to remove the confusion and intimidation many feel. We kick off this four-week series with a running program courtesy of Andrew Lockton ( www.andrewlockton.

Many adults know how to swim -- that is, they can get from one end of the pool to the other without too much trouble. But to swim proficiently and with finesse, they must learn to properly stroke, kick and breathe. That's where swim coach Nancy Kirkpatrick-Reno comes in.

Hiking trails are good for more than a challenging outdoor walk. The uneven terrain forces the body to use more stabilizing muscles in the abdominals and back, which improves balance and strengthens the core. Sprints or walking fast uphill puts you into an anaerobic zone, which taxes the muscles and benefits the cardiovascular system. We took to some trails near Jet Propulsion Laboratory in the San Gabriel Mountains foothills with Keli Roberts ( www.keliroberts.

For decades, fitness gurus have admonished sofa spuds to adopt a can-do attitude toward exercise, as if the only thing keeping them from the gym or walking path was the right attitude. Yet a growing body of evidence suggests that it's not merely motivation but also genetics that separate slouches from fitness fanatics, and at least some of these genes appear to act on the brain's pleasure and reward center. Though the science doesn't imply that people disinclined to exercise can't get moving, it helps explain why some people find it more difficult than others to "just do it."

CellPHONES and PDAs can do more than ensure we stay in touch and keep appointments. A new study shows that middle-aged and older people who received daily reminders to exercise from PDAs put in more than twice as much moderate to vigorous exercise than those without the devices. Such cues "bring the priority of exercise back to the top of the list," says Abby King, lead author of the study and a professor of health research and policy, and medicine, at the Stanford University School of Medicine.

Race cars often don't have a speedometer. What they do have is a tachometer that shows how fast the engine is revving. A heart rate monitor is a tachometer for the human body -- it tells a user how quickly the heart is beating during exercise. Sports- and fitness-related use of the device has mushroomed since its invention in 1977, but many people don't know how to use one effectively. For starters, simple formulas to determine heart rate training zones aren't reliable.

You roll around on your Swiss ball like a grizzly with a back itch. You do crunches and work your obliques like a champ. So you must have good core stability, right? And core stability will reduce back pain and prevent injury, right? Yes, no, maybe. Research on back pain, experts say, is frustratingly spotty and the subject of debate.

Fitness author Jorge Cruise doesn't agree with the Borg admonition that resistance is futile. In fact, he believes that just a few minutes per week of properly applied resistance exercise can firm muscles, build lean muscle tissue and trim inches off the waist. Cruise, who writes a weekly column for USA Weekend, is also the author of "8 Minutes in the Morning" and "The 3-Hour Diet."

Getting kids to exercise more and cut down on television watching can dramatically reduce their risk of being overweight. No surprise there. We even know just how much activity they should have and how little TV they should watch. And still the job is apparently Herculean for kids to do and parents to enforce. The American Academy of Pediatrics has recommended that boys take at least 11,000 steps per day, girls 13,000 steps per day, and total screen time should be limited to two hours per day.

For people living with chronic pain, exercise is often the last thing they want to do. But physical activity could be a key component of some treatment plans, new studies suggest, especially with conditions such as fibromyalgia and arthritis. "The pain doesn't go away completely. It's not a cure. But it's a way to improve how you feel and your ability to function in daily life," says Daniel S.