BUT IT IS TRUE. To kids anyway (and me.... and maaybe some of you out there too). I train kids, a lot. Sometimes we work with weights and I always have at least one concerned parent ask me if it's safe and "am I sure because I heard they shouldn't be lifting weights". Blog post time!
MYTHS: The most common myth surrounding kids and weightlifting is that it will stunt their growth. This myth stems from a Japanese study done on exceptionally short child laborers. The study chalks up the children's shortness to all the heavy lifting and manual labor they did. These results were adopted around the world and weightlifting was deemed unsafe for children.
Many studies have been conducted on this subject and the results found contradict the Japanese study. "It is now well established that not only is it safe to the developing musculoskeletal system of children to perform resistance training it is also effective in developing strength, increasing bone density and preventing sports-related injuries" (Heavey). Like anything in life, if it's done too much and not correctly it is harmful.
I'm sure if kids perform heavy manual labor for hours a day, everyday, it effects their growth and general health. Even if they workout everyday unsupervised (or not supervised enough) with too much weight it will probably not have the best results. But the Japanese child laborers and unsafe weightlifting habits shouldn't be grouped with children who are weightlifting under proper supervision at the gym.
KIDS EXERCISING: Kids process things differently than adults and their workout style needs to reflect that. Naturally, kids workout and function optimally in short powerful bursts (this may or may not have to do with their attention span or lack thereof;). So that means they want to go as hard as they can for a short time then rest/do something different; aka anaerobic exercises. Weightlifting is anaerobic exercise! This enables kids to go hard for a little while and then take a break/mix it up. This results in having fun exercising; which results in healthier kids; which results in healthier adults. I'm not saying your children should only weight lift... running around and playing is great exercise too. Combining the two results in healthier, stronger kids!
OVERWEIGHT CHILDREN: I've seen many a well intentioned parent put their overweight/unhealthy child on a treadmill/bike/elliptical for 45min and the child has fought them or just slacked off the entire time. No one likes doing new things especially if they aren't good at them and it's just plain boring. Cardio burns more calories in the moment but it is shrinking both muscles and fat. Weight training burns more calories and fat in the long run because your metabolism stays elevated after you train and larger muscles burn more fat, but that's a whole blog post in itself! Overweight kids usually excel at weight training simply because they have more weight to put behind the exercise, it is constantly changing, and it makes them feel confident. Once they see that they are strong and might even be able to lift more than "Bobby" who always outruns them, working out turns into something they want to do.
PARENTS: Weight training is great for adults because it builds your bone density(no osteoporosis!) strengthens connective tissues, boosts balance, improves your mood, burns more calories(because of your extra muscles), and lowers your blood pressure. It does the same things for kids! Kids that lift weights are stronger and have better body balance so they are less likely to be hurt playing sports or in everyday life. 2/3rds of injuries sustained by 8 to 13 year olds happen on their hands or feet caused by dropping weights or being careless, nothing to do with stunting growth!
So think about weight training for yourself and your kids, it will help you and them in the long run! Exercising together is just an extra bonus :)