A Porirua principal has called ACC's adopted advice of one hour of organised sport per week for every year of a child’s life "nice" but unrealistic.
"I think the push for balance is the really important part… we have people that play for New Zealand and our students, when they’re heading for that dream, they’re not going to get there if they’re doing 14 hours a week when they’re 14," Porirua College principal Ragne Maxwell said.
"We’ve also got to have a sense of reality about what the students are going to do and we have to teach them how to manage themselves."
Ms Maxwell said she wished society would just let children be children "before we push them" but with sport being highly-competitive, it was a school’s responsibility to help enable students to live in the "real world."
ACC today revealed there's been a dramatic increase in the number of kids claiming for sport-related injuries over the last decade, as high performance training increases for school-age athletes.
"We push them too hard, too soon, they're at risk of injuries and not achieving those goals," ACC Head of Injury Prevention Isaac Carlson told 1 NEWS.
From 2008 to 2017/2018, the number of injuries reported to ACC for those aged 10-14 years old has increased 60 per cent, to more than 40,000 claims.
For teenagers aged 15 to 19, ACC injury claims have increased 29 per cent over the same period, to more than 45,000.
Mr Carlson pointed to kids being identified for a professional career in sport and training for a single sport from a young age as a global trend, along with an increase in high-intensity trainings and more sport sessions per week for kids.
"We’re finding young kids are increasingly in one of two camps; those not doing enough exercise who may be putting themselves at risk of injury because they aren’t conditioned for activity; and in growing numbers, those that are engaging in higher levels of sport and training and aren’t getting enough of a break," he said in a statement.
Ms Carlson said ACC is encouraging parents and coaches to make sure a child’s weekly exercise does not exceed their age, a guideline taken from the Australasian College of Sport and Exercise Physicians.
"That’s what the evidence suggests will help them perform at their best.
"It's not uncommon to see young people that will be playing for a school, a club, a representative team… all at the same time so it's quite easy for those hours of structured activity to mount up," he said.
Physiotherapist Sharon Kearney said it’s not appropriate for high schools to offer high performance training.
"The kids are not mini adults, they are adolescents with immature musculoskeletal systems," Ms Kearney said.
She said when children are trained with the workload of a high-performance adult athlete, the outcome can be injury as their bodies cannot handle "that level of loading".
Apart from the long-lasting effects of a childhood injury, the Australasian College of Sport and Exercise Physicians reports over-training can lead to early burn out and mental health issues in later life.