Faigenbaum et al, (2015) provides the following benefits:
The major concern for parents and scientists is the possible damage to the epiphyseal growth plate. The structural compound is weaker than the surrounding tissue, however there is no evidence to suggest that weightlifting or more general resistance training is especially injurious to the epiphysis. (Pierce et al, 2008)
Other challenges are an unsafe environment and equipment, excessive load and volume of training. The instructor not qualified to undertake a resistance session.
The long term athlete development (LTAD) model is encouraged when exposing young athletes to specific training.
This is a breakdown of the LTAD training Lyold et al, (2012) has recommended.
Stage 1: FUNdamental weightlifting 6-9 years. Innovative games should be used to incorporate desired movement patterns. No weights are used just movements that incorporate t-spine extension, scapula stabilization, core strengthening and triple extension.
Stage 2: 9-12. Structured training becomes more relevant and session become more specific to weightlifting. Athletes are still not lifting weight. Athletes are introduced to the different phases of each lift, with technical competency of primary concern.
Stage 3: 12-16. At this age the coach must pay attention to the athletes growth. It is imperative that coaches monitors growth rates and are sensitive to sudden interruptions in technical competency.
Stage 4: 16+. The last stage allows younger athletes to be exposed to more advanced training, program design, technical expertise and external loading.
Opinion on Youth Strength and conditioning
I feel that to progress our younger players youth conditioning is necessary. It is important that it not be seen as strength training because at this young age it is movement that is of primary concern. Movement is being thought too late in the minor set ups around the country. Instead of having technical competency at the age of 16 and 17, our minors are only just learning to get their technique right. They have missed the stage where their brains are most likely to absorb new movement patterns. They have the difficult process of trying to retrain bad movement that we have allowed them to get into. Therefore younger athletes at ages of 12+ should be learning technical competency and by the time they reach 16 and 17 they can put on external load without fear of incorrect movement leading to injury. This will progress our players, making them much more athletic and less likely to get injured.
What to look for
A qualified strength and conditioning coach that can implement youth strength and conditioning. Youth strength and conditioning is already happening in a small number of counties and it is showing major benefit when players reach minor and senior level.