At what age is it okay to let a child start to lift weights to help with sports performance?

His decision: Let him decide. The ohnly supervision required is that the weights are proportional to the age and strength of the child.

Use a trainer: Weightlifting like many sports activities can be beneficial if done right & can produce significant injury if done wrong. Any pre-teen/teen should be supervised by a professional, preferably one certified in the area.Early training focuses on technique & low intensity weights. Power lifting & body building are not recommended until the kid reaches skeletal maturity (final height, b.O., shaves).