Experts say children and teenagers should not practice boxing because their brains are more vulnerable to acute and chronic injuries caused by blows to the head.

In a statement, the American Academy of Pediatrics (AAP) said thousands of boys and girls participate in the sport in North America, despite risks of serious brain and facial injuries.

There is very little one can reasonably do in order to increase the chance of having a healthy brain when you get old, said Dr. Hans Forstl at the Technische Universitat Munchen in Munich, who has studied boxing injuries. One of the best things you can do is avoid boxing.

However, the new move met with fierce resistance from the boxing community.

Pat Russo, a retired police officer who runs a boxing gym in Brooklyn, New York, told Reuters that the sport has helped thousands of kids in poor neighborhoods find direction in life.

Boxing has been a kind of penicillin for these kids, it has been saving these kids, he told Reuters. It teaches them discipline and a work ethic that if you do something and you practice every day, you are going to get better at it.

According to the new research, published in the journal Pediatrics, data from Canada show a rise in boxing injuries over the past decade.

From 1999 to 2007, the injury rate jumped from 11 to 16 per 100,000 kids, with most of the damage done during sparring or competitions.

One study cited in the research estimated that for every 1,000 hours of amateur boxing, there would be one injury, which is lower than the rates in football, wrestling and soccer.

Boxing is one of the very few sports which really aim at hurting the opponent and for a short period of time achieving loss of consciousness, said Forstl. A knockout is basically a cerebral concussion.

Concussions are the biggest concern, ranging from six to 52 percent of all injuries, according to one study.

The typical brain of a boxer with a long career shows severe changes, Forstl said.