DOTHAN, Ala. Missy and Marvin Sexton recognized the signs.
Their sons Walker, 12, and Greg, 9, were spending more time with computers and electronics and less time playing outside.
The parents took action in January, setting up a system where the boys had to earn their electronics privileges through exercise.
"We decided it was getting too much," Marvin said. "To stay physically healthy, I think you have to set a foundation for the kids going forward, to teach them that exercise is important and to stress it, to get them outside doing things."
If the boys don't earn the required exercise points, they don't get to play computers.
"And they've never failed, every single month," Missy said.
The system isn't complicated. At the end of each day, Missy figures out what the kids have done and totals up the points. She also monitors the amount and kinds of food they consume.
The fitness and diet regimen isn't just for the kids. The parents work to set a good example, and use activities with their sons as family bonding time.
"We jump on our bikes together and have adventures," Missy said. "Remember that 12-mile adventure down at Panama City?"
They pedaled through creeks and racked up memories.
"This past summer we went up to Chattanooga and all we did was hike every day," she said. Climbing over boulders, talking and playing helps them make a healthy lifestyle both workable and fun.
As a pulmonologist, Marvin sees the problems when kids don't develop good habits on diet and exercise.
"Kids that have never gone outside and played and exercised in a structured fashion, they'll never get that," Marvin said. "I see that all the time in my practice, people 20 years old who weigh 500 pounds, and it's solely through lifestyle issues."
Missy said kids pick up cues about food and fitness from their parents. "They didn't see their parents exercise so they don't understand," she said.
Pulmonary (lung) fitness is tied to cardiovascular fitness - the ability to exercise vigorously for a long time, such as running laps on a track. Increases in fat mass usually are mirrored by declines in running performance.
Research presented last month at the American Heart Association's Scientific Sessions 2013 concluded that children's cardiovascular fitness worldwide has declined 5 percent per decade since 1975 for children ages 9 to 17.
Kids don't run as far or as fast as their parents did, and that may indicate worse health in adulthood.
The findings are no surprise to Dr. Ted Williams and other doctors at Southeastern Pediatric Associates.
"This is something we've seen coming in pediatrics for the last three decades," Williams said. "We've become a fast-food generation. There's no family dinner table. We have no portion control. We're eating a diet that predisposes itself to obesity, and we know a significant number of children are obese."
Williams sees multiple factors at work. "Our diet has drastically worsened over the last 30 years," he said. Kids are getting much less exercise than they used to and are spending more time in front of television and computer screens.
"Those kids who are less fit now have significant health issues as they go along," Williams said. "Twenty to 30 years ago, we never heard of type 2 diabetes in children. That's diabetes caused by insulin resistance, and now that's a leading cause of diabetes in children."
He said it's directly related to obesity, which is directly related to lack of exercise and improper diet. "So we have a generation of children that are going to be more at risk for cardiovascular disease, high blood pressure, elevated cholesterol and diabetes, and almost all of this is preventable," he said.
"We call it in pediatrics the new morbidity," he said. "We used to be concerned about measles, chickenpox, whooping cough, tetanus, polio, all these diseases. Well, we have vaccines now for those diseases, and so now parents aren't faced so much with those challenges as they are with the challenges of diet, exercise and how you manage this electronic age."
Williams said computers and other technological advancements are a great aid to education and parents, but like food must be taken in moderation.
"I see a lot of children eat the right foods, they just eat twice as much as they need," he said.
Williams said parents need to provide leadership on health and nutrition.
"I talk about this every day in my office because we see so many kids who are significantly overweight who don't necessarily want to be that way, but they have to eat what's put on the table, they can't go out and get their own diet," Williams said. "So I try to approach the parents, saying let's make our diet as nutritious as we can and let's lead by example. If they see you out there walking or riding a bicycle, then they're more likely to do that."
Doctors and parents can provide guidance to lead children toward a healthier lifestyle, but there are other kinds of help available.
Rosalind James, a regional Extension agent with the Alabama Cooperative Extension System, said ACES is partnering with Dothan City Schools to hold a Teen Health Fair on March 7 at the National Peanut Festival Fairgrounds.
Starting in January, 32 Northview High School students who are 4-H club members in the Health Education Leadership Program will be visiting elementary schools to teach third to fifth-grade students how to eat properly and increase their physical activity.
James said the national 4-H council believes the program will be effective because young students are likely to listen to older students who have gone through the same problems.
"You have one body and you've got to take care of that one body," James said. "When you don't feed the body the right foods (like fresh fruits and vegetables) and you're not exercising, you're going to be subjected to all these chronic diseases."
Becky Tew, a physical education teacher at Honeysuckle Middle School, said she has seen a decline in cardiovascular fitness among students during the nearly 30 years she has been teaching.
"The challenge I find is it is more challenging to motivate students to play and participate, whereas in earlier years that really wasn't a problem, you might have one or two," Tew said. "We're having a larger majority of kids, they would rather just sit down and play games on the computer or just talk."
She said the problem is worse among girls than boys.
At the middle school level, the instruction focuses on fitness, conditioning, introduction to different activities, warmup, sportsmanship and basic rules. "At seventh and eighth grade they can start participating on the athletic teams," Tew said.
Classes are about 50 minutes long, but some of that time is spent in the dressing room or in warmup activities. In class the students can get just more than half of the 60 minutes of daily moderately vigorous activity recommended by health experts for children age 6 and older.
Brittany Melvin, store manager at Love 2 Run, said people who come to the store are usually already motivated to get more active.
Ages range from young to old. "Some people, their doctor recommends that they need to get in shape," she said. Others have been diagnosed with diabetes or heart disease.
Melvin said employees listen to people to assess their needs. "We don't want to make them think that they have to run because we want to still promote fitness, even if it does mean walking," she said.
Setting goals, like putting in a set number of miles per week or running or walking in a 5K, is important. "When you feel like you have to meet a goal, you don't want to let yourself down or anybody else that knows that you're going to try to meet that goal," she said.
Working exercise into a schedule is sometimes the biggest challenge. With parents working so much and kids sometimes kept indoors because of unsafe neighborhoods or lack of supervision, it can be difficult for children to get enough exercise.
Dr. Williams said the research indicates the fitness decline probably has flattened out in the last two or three years in this country. "People are becoming a little more concerned about it, everything from the first lady to school officials are seeing the need for more vigorous exercise programs and really putting emphasis back on being fit," he said.
Battling the convenience of cheap, high-calorie foods and finding the time to instill good habits in children is the challenge. How the situation will play out for the world's population is anyone's guess.