The claim sources are saying is that weight lifting can stunt your growth. Due to research I found that weight lifting does not stunt your growth. But it warns young teens or younger users of weight training, that trying to constantly hit your max weight, can cause injury. "Strength training does not stunt growth….however, maximal lifting (highest weight amount you can lift one to three times) may put you at more risk for injury to the growing areas of a child’s body. Therefore, max lifting should be discouraged until after puberty" (University Hospitals).