MY KIDS GET IN THE WAY

After giving birth in 2003, Nancy Toby really wanted to get back to her regular exercise routine. She missed training for marathons and triathlons and the stress release it offered. Her triplets were born prematurely with health problems, and one baby died six months later. "I needed some time to myself," she says. "Exercise really helped me recover and keep a level head." The 48-year-old in Arlington, Va., has returned to her training regimen and plans to take on an Ironman triathlon in November. Toby fits it all in by going to the gym early when her husband and two 3-year-olds are sleeping. She also walks with her double baby jog stroller and, when her husband is around to watch the kids, rides her bike on a stationary trainer set up in front of the television.

Some parents incorporate their children into the activity. Mom and baby yoga classes are popping up around the country, while some workouts use baby strollers. And, of course, many gyms provide childcare facilities. When the kids get older, exercise can be viewed as family time. "Go bike riding, or hiking, or kayaking, or Rollerblading, or play tennis with your family," says Kathie Davis, executive director of the IDEA Health and Fitness Association. "If they see you exercising, they're going to model your behavior."

MY BACK HURTS

Used to be that people with constant back pain were told to stay off their feet. No longer. "The general dogma for chronic back pain is that moving your body is a good thing," says Karen Sherman, a researcher at the Group Health Cooperative, a Seattle-based nonprofit health system. In fact, studies have shown that people with chronic back pain and disk degeneration were helped just as much by exercise as by spinal fusion surgery.

Talk to your doctor or physical therapist about specific exercises to strengthen other muscles and take some of the load off your back or stretches that can help minimize pain. A study by Sherman published in December in the Annals of Internal Medicine found that yoga may be especially helpful in keeping chronic back pain at bay. But be forewarned. Some yoga classes might be too strenuous. The class in the study "was gentler and simpler," says Sherman, who advises that back pain sufferers ask a health professional for referrals to classes aimed at people with special medical needs.

I'M TOO FAT

Unless you are severely obese, excess girth isn't a good reason to remain sedentary. Anyone with a body mass index (a measure of body fat taking into account height and weight) between 25 and 30, considered overweight, should be able to exercise, says Ribisl. As the BMI climbs above the 40 mark deemed morbidly obese, there are increasing risks, he says, such as strain on joints or the heart. "The key word is individualization," says Ribisl. For obese people, "the intensity would have to be lower, the duration would have to be shorter." A small study in the Archives of Internal Medicine in April revealed that elderly and frail people who were obese benefited from six months of regular exercise and a healthier diet. The group lost an average of 8.4 percent of body weight and improved strength, walking speed, and balance.