In addition to playing outside and participating in sports, your kids may want to lift weights, join CrossFit classes or do some other form of strength training. But is this a good idea for children, or will it harm their growth and cause injury?
"Strength training programs are almost essential in our society because we have so little opportunity" to build strength in daily activities, says Wayne Westcott, PhD, exercise scientist at Quincy College. Strength training, also called resistance training, might involve the use of free weights, weight machines, elastic tubes or the child’s own weight. There’s never been a study to show that strength training stunts growth, says Westcott. "In fact, the opposite is true." Westcott, who studies the health effects of strength training in children, says that, for example, a 9-year-old girl using dumbbells and elastic bands for 10 months could expect her bone density to increase by (an average of) six percent compared to just (an average of)1.5 percent if she did not strength train.
Strength Training May Prevent Sports Injuries
The American Academy of Pediatrics (AAP) also supports strength training for children and adolescents. In fact, the AAP says that strength training for kids 8 years and older is safe and may be an effective way to prevent some of the 3.5 million sports related injuries to children each year.
Strength training among youth does more than improve body composition and cardiac fitness, says Melissa Joy Dobbins, MS, RDN, LDN, CDE, spokesperson for the Academy of Nutrition and Dietetics. "It also improves blood cholesterol, bone density and even mental health," she adds. "As a mom and a dietitian, I know how important it is to be a good role model. I'm a big fan of strength training for health. I've done it myself for more than 20 years and now my daughter wants to start too." And don’t worry that children will bulk up like miniature Hulks. According to the AAP, youngsters will get stronger without increasing their muscle size until they hit puberty.
What Is CrossFit?
One increasingly popular training class is CrossFit, an intense strength and conditioning program that focuses on explosive muscle action and includes jumps and Olympic lifts. In addition to weights, CrossFit uses nontraditional weightlifting equipment such as sandbags, tires and kettlebells. But should kids be participating? "CrossFit is not for the faint of heart," says Jennifer Neily, MS, RDN, CSSD, LD, specialist in sports dietetics and nutrition coach in private practice. It's more suited to the advanced athlete who enjoys high intensity, vigorous activity and wants greater variety in a fitness program, she adds. Westcott agrees. "It’s way over the top for those simply interested in health and fitness."
However, if you work with a coach who is trained in child development and conducts a class that is less intense and is appropriate for children, CrossFit can be fun and safe for kids, says Neily. For example, climbing ropes is a great activity, but kids shouldn't be doing strength moves such as the clean and jerk. Whether it's CrossFit or any other program, consider your child's safety and the qualifications of the trainer. You can enroll your children in strength training programs once they show the emotional maturity to follow directions and the desire to participate in the activity. "Brief and basic is best for kids," says Wescott.
Best Strength Programs
A good program starts with active games, includes 20 to 25 minutes of weight training and ends with more fun and games with a focus on motor skills. Westcott prefers programs that have kids use external resistance like bands, dumbbells and child-size machines instead of the child’s body weight. This way they can start with very low resistance and add resistance as they build strength. According to the AAP, a well-supervised program has a coach-to-student ratio of 1:10 or less.
Strength training is not recommended for children with uncontrolled high blood pressure, seizure disorders or a history of chemotherapy for prior cancer treatment.