A different perspective: The intensity of these routines has increased drastically in the past ten years. On Youth and Jr teams, you have a wide growth gap, and these kids are throwing much lighter flyers than themselves. On Sr. aged teams, the growth gap is much smaller. I'll preface this by stating I don't want to get into a flyer size debate, we need to be sensitive to weight issues with flyers, but with that said, physics can't be ignored when it comes to our bases and backs joint and tendon health either. When it comes to lower level Sr. teams, these athletes do not have the muscle development these level 4-6 athletes do. While on a Sr. 4.2 my oldest helped out on a Sr. 2 and said there's a HUGE difference between a 115 lb flyer that can help lift and hold their weight in the air, versus an athlete where you are doing a lot of the lifting and fighting to keep them in the air. She, also, said there's a HUGE difference between catching 115 lbs when you have shoulder, arm, core, and leg strength versus when you don't. While she would agree many lower level Sr. aged athletes would quit before being on a Jr. team, she also said there were many that quit because of repeat injuries. Another difference in the past ten years, are organized sports have changed the dynamic. Now, most kids have been in their sport for several years by the time they get to HS. It used to be that you would have 14 year old's changing their sport and trying something new at that age, but now if you're not proficient at that age, you generally aren't able to participate. Even ten years ago, it was very hit or miss if my kids had a Sr. level 1 or 2 team to go up against.