How much exercise is safe for kids?

By: Morgan Griffin

What should you do if your 10-year-old wants to lift weights? Or your teen goes on daily runs even though she plays a sport, too? Getting exercise is good for kids -- they need at least 60 minutes a day. But is there such a thing as too much exercise for a kid?

Most Kids Need to Move More
The truth is a majority of kids aren’t getting enough exercise. According to a 2012 YMCA parent survey, only 19% of kids were getting the recommended amount of physical activity. The good news is it’s never too early to help your kids fall in love with fitness. That way moving and being fit is just a natural part of life.

“We don't have guidelines about what age a child should start a specific physical activity," says Joel S. Brenner, MD, chair of the American Academy of Pediatrics Council on Sports Medicine and Fitness.

Some 10-year-olds can run 5K races without any problems, and even weight lifting -- as long as it's supervised -- can be safe for young kids, he says.

How to Keep Kids Safe
So how do you know if it’s too much too soon? It all depends on your kid, say experts. You don’t have to be nervous as long as you keep an eye on things.

Here’s how to guide your child’s physical activity to make sure she stays safe:

Have them rest. The American Academy of Pediatrics says that kids playing organized sports need at least one day off a week. They also need two to three months off from training each year.

Why? Exhaustion. "These kids can still be active doing other things," says Brenner. But their bodies and minds need time to rest from the rigors of practice.

Kids are going to be tired after practice. But if your kids have night games or are getting up hours before school starts to work out, they may not be getting enough sleep. That can affect their health, mood, and performance at school. Remember, school-age kids need at least 10 hours of sleep a night. Teenagers need at least 8 1/2 to 9 1/4.

Increase workouts gradually. Don't allow your kids to rush and rapidly up their workouts. They shouldn’t increase their exercise -- the amount of time, number of repetitions, or distance -- by more than 10% in a week.

Why? Injuries. Big jumps in training can lead to injury. Overuse injuries are common in kids who exercise heavily, says Brenner. By pushing themselves too hard, they have a higher risk of stress fractures, shin splints, and other problems. Their growing bones can't handle the physical stress as well as adults' bones can. They can develop lasting muscle and joint injuries.

Allow for spontaneous play. Your kid's physical activity shouldn't all come from organized athletics. "Kids need time for running around in the neighborhood with friends," Brenner says.

Why? Burnout. "Playing a sport can have a huge mental toll," says Brenner. If your kids push themselves too hard, they get worn out. They may give up on sports completely before the end of high school. You want to encourage a lifelong love of being active.

Get help. If your kid's exercising seems too much -- or you're noticing big weight or behavior changes -- see your child's doctor right away.

Why? Other health problems. Too much exercise is closely related to eating disorders and body image problems. Both guys and girls can be affected by eating disorders, and they can be very dangerous.

In girls, too much exercise can cause changes in hormone levels. They may not hit puberty or menstruate normally. They also have a higher risk of weak bones.

Ways to Stay Involved

So how can you tell if your child is headed down the wrong path? Be an involved parent.

1. Watch the coaches. "Coaches are instilling their own values in your kids," Brenner says. Are those values you agree with? Are they worried more about winning than your child's well-being? If so, you need to step in.
2. Talk about it. Have honest conversations with your kid about how things are going. Kids may push themselves in sports to please coaches, friends, college admissions officers -- and you, Brenner says. They may feel pressured to do it even if they don't want to anymore. Be open to your kids changing direction, if they want.

"For kids, exercise is supposed to be fun," says Brenner.