“Physical activity is extremely important for enhancing quality of life and decreasing the risk of chronic conditions,” says Wojtek J. Chodzko-Zajko, Ph.D., an expert on exercise in older adults and dean of the Graduate College at the University of Illinois at Urbana-Champaign. But that knowledge doesn’t always translate into practice: The Centers for Disease Control and Prevention (CDC) estimates that almost a third of adults age 50 and older get no exercise at all.

“It’s very difficult to tell someone what to do if they aren’t self-motivated to do it,” says Chodzko-Zajko. “We used to talk about an exercise prescription, where the doctor would tell the patient what he or she needs to do. I think it needs to be more of a bidirectional dialogue—jointly focusing on how to increase the amount of time you exercise.”

Here’s how to begin that conversation so that you and your parents can enjoy the life- and memory-extending benefits of an active lifestyle for many years to come.

Talk to your parents about what’s important to them as they age. “Ask them to think about where they want to be 10, 15, or 20 years down the road,” says Chodzko-Zajko. “Maybe they want to be able to go shopping whenever they want. Or maybe they want to be able to live by themselves in their own home.”

Once you’ve established the motivation, it’s important to make the link between that goal and being physically active. For instance, in one study of more than 1,600 sedentary men and women age 70 to 89, those who started a moderate-intensity exercise program were 18 percent less likely to become disabled during the two-and-a-half-year study period. Need some extra ammo? Check out The Simple Fitbit Fitness Check That Can Help You Understand Your Heart and 9 Reasons to Give Your Dad a Fitbit Tracker.

Does your dad like to swim? Does your mom like to dance? “A lot of that generation believes that in order to get in shape, they need to belong to a gym,” says Lisa Reed, a personal trainer in Washington, D.C., who has worked with dozens of older clients. “And that’s just not true.” Swimming, walking, dancing—they all count as movement, and the less it seems like work, the more likely they’ll be to stick with it.

While the government recommends 150 minutes of moderate to vigorous exercise per week, that can be an insurmountable task for someone who isn’t used to exercising. So start your parents at an appropriate level.

Chodzko-Zajko tells the story of his 60-year-old schoolteacher mom, who would come home after a long day and want nothing more than to put her feet up. Instead, he encouraged her to walk to the shops at the end of the street. She did that three times the first week and four times the second, after which he urged her to walk a block further and so on. “She had been listening to the experts on TV who were telling her to exercise for 30 minutes 5 days a week and for her, that was tantamount to saying, ‘Go climb Mount Everest.’” Now 87, she attributes her longevity to that ingrained walking habit.

When Chodzko-Zajko instructed his mom to walk to the shops on the corner, he also told her to put a check mark on her calendar every day she was able to achieve this goal. The checkmarks served as a kind of reward and further motivated her to get out of the house the next day. Your parents can do this with any standard calendar or planner, or they can monitor all exercise and active minutes via the Fitbit app. Some trackers, like the Fitbit Alta HR, even detect and log activities automatically. “Activity trackers are incredibly useful because they allow an individual to assess what they are currently doing and set goals to increase their physical activity,” Chodzko-Zajko says.

It will help keep them motivated and accountable. “They just need that one friend who will go for a walk and not cancel,” says Reed. Group personal training is also a great option. Reed works with three women between the ages of 68 and 72, one of whom has had both knees replaced. “We work on balance, posture, and core strength,” she says. “It’s more economical when you split the cost, plus it’s a small enough group that we can focus on [appropriate] exercises for each person.”

Exercise is hugely important, but moving more outside of a traditional workout should also be non-negotiable. According to the American Heart Association, regular exercise may not be enough to negate the negative effects of too much sitting. Show your parents how to move more all day long by doing things like swinging their legs while standing at the counter or balancing on one leg while they brush their teeth. “It’s all about moving just a little bit more each day,” says Reed.

If your parents use a Fitbit Flex 2, Fitbit Alta, Fitbit Alta HR, Fitbit Charge 2, or Fitbit Blaze, they can also turn on Reminders to Move, which will give them a gentle nudge every hour if they haven’t taken at least 250 steps.