It’s never too early to encourage a love of physical activity in kids by exposing them to fun fitness activities and sports. Doctors say that participating in different activities develops motor skills and muscles and reduces the risk of developing overuse injuries.

In the Physical Activity Guidelines for Americans, the U.S. Department of Health and Human Services (HHS) recommends children get at least one hour of exercise every day. This may seem like a lot, but it’s easy to see how the minutes can add up when you consider all of the running and playing an active child does on a daily basis.

Here are some guidelines to help you choose age-appropriate fitness activities for your kids.

Preschoolers can play team sports like soccer, basketball, or T–ball as long as your expectations are realistic. Any sport at this age should be about play, not competition. Most five-year-old children aren’t coordinated enough to hit a pitched ball and don’t have true ball-handling skills on the soccer field or basketball court.

Preschoolers tend to love water. It’s fine to introduce kids to water safety between six months and three years old. The American Red Cross, the country’s leading water safety and instruction organization, recommends that preschoolers and their parents first enroll in a basic course. These usually teach blowing bubbles and underwater exploration before starting formal swimming lessons. Children are ready to learn breath control, floating, and basic strokes at about age four or five.

Children have developed enough by age six that it’s possible for them to hit a pitched baseball and pass a soccer ball or basketball. They can also do gymnastics routines and confidently pedal and steer a two-wheeled bike. Now is the time to expose children to diverse athletic and fitness-related activities.

Different sports stress growth plates differently, and the variety helps ensure healthy overall development. Overuse injuries (such as stress fractures and heel pain in soccer players) are increasingly common and happen when kids play the same sport season after season.

Hand-eye coordination really kicks in at this point. Children are usually able to hit and accurately throw a baseball and make solid contact with a golf or tennis ball. It’s okay to encourage competition, as long as you don’t put all the focus on winning.

If children are interested in participating in events such as short triathlons or distance running races, these are safe as long as children have trained for the event and maintain healthy hydration.

Kids may lose interest in the structured environment of organized sports as they reach adolescence. They may wish to focus instead on strength- or muscle-building exercises. But unless your child has entered puberty, discourage lifting heavy weights.

Encourage healthier options, such as stretchy tubes and bands, as well as body-weight exercises like squats and push-ups. These develop strength without putting bones and joints in danger.

Prepubescent kids should never attempt a one-rep max (the maximum weight a person can lift in one try) in the weight room.

Children are at the biggest risk of injury during periods of growth spurts, such as those experienced during the early teenage years. A child who lifts too much weight or uses incorrect form when throwing or running can sustain significant injuries.

Once your teen has gone through puberty and is ready to lift weights, urge them to take a weight-training class or a few sessions with an expert. Poor form can harm muscles and cause fractures.

If your high schooler expresses interest in endurance events like triathlons or marathons, there’s no reason to say no (although many races have minimum age requirements). Remember that proper training is just as important for teens as it is for their parents. Just keep an eye on nutrition and hydration and learn to recognize the signs of heat-related illness.

Building a healthy foundation is important for raising children to be healthy adults. Children are naturally active, and encouraging this with fitness guidance will create lasting habits.