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The hormones needed to grow big, bulky muscles come with puberty, so do not push a child to lift weights or start training plans when they cannot even reap the rewards. Kids will start to build muscle naturally as teenagers, but kids should be focused less on growing muscles and more on being healthy. Weightlifting, body building, and power lifting can all be very dangerous to a child’s still-developing muscles. Strength training, however, is focused on proper technique and safety instead of lifting the biggest piece of metal you can. Weightlifting as a child can damage a kid’s growth plates, which are pieces of cartilage still turning into bone, injuring a child for life. Make a distinction between increasing muscle strength and “bulking up.” Talk to them about the benefits of having lean muscles such as a healthy weight, improved performance in sports, and higher self-esteem. Let them know that it is impossible to "bulk up" a lot of muscle before puberty. If a child can follow directions well and expresses interest in getting stronger, you can safely begin a light workout plan as early as 7 years old. If a child is ready to play organized sports, they are generally ready to start a strength program. Weightlifting, body building, and power lifting can all be very dangerous to a child’s still-developing muscles. Strength training, however, is focused on proper technique and safety instead of lifting the biggest piece of metal you can. Weightlifting as a child can damage a kid’s growth plates, which are pieces of cartilage still turning into bone, injuring a child for life. Make a distinction between increasing muscle strength and “bulking up” with your child by talking to them about the benefits of having lean, strong muscles, such as a healthy weight, improved performance in sports, and higher self-esteem.</ref> Since most children cannot actually build muscle, you should work on the proper exercise techniques to prevent injury, learn good mechanics, and set a good foundation for later workouts. Some things to look out for include:  Keeping your back (spine) aligned. Your lower back should never bend forward or backward to make a stretch easier. Focus on keeping your chest up and shoulder blades back so your back is flat. Never “hyperextend” a joint. Hyperextension is when you bend a joint slightly the opposite direction as it is supposed to, like straightening your knees so much that your legs curve backward.  Work on healthy running form. Good runners keep their backs straight, land in the middle of their feet (not on their heels) and take medium sized, quick strides instead of long steps. Kids are trying to learn complex motions at the same time as they build muscles, and this is difficult when they are first starting out. You need to watch kids and help them fix posture, avoid injuries, and work out effectively to avoid injuries.
Remember that kids are not likely to grow muscles before puberty. Focus your energy on strength training, not weightlifting. Know that a child can start strength training around age 7 or 8. Focus your energy on strength training, not weightlifting. Prioritize proper technique over big muscles. Supervise a child as they learn strength training.