Key Points:

The cost of treating sporting injuries has skyrocketed over the past three years, with taxpayers forking out nearly $70 million in the last year alone.

In its last financial year, the Accident Compensation Corporation paid out $69 million - up 58 per cent from two years ago - to treat people who hurt themselves taking part in New Zealand's top 10 sports.

Concussion, shoulder injuries, hamstring, knee and ankle strains were the most common injuries ACC funded treatment for.

While hard impact and frequent collision sports dominate the ACC's top-10 list of sports injuries, each year the taxpayer subsidises the treatment of people who hurt themselves in supposedly more sedate pursuits, such as lawn bowls or yoga.

The national game, rugby, comfortably dominates its rivals in the injury stakes, with more than 49,000 rugby players injured last year.

Soccer and netball, two of New Zealand's biggest sports in terms of playing numbers, have consistently filled second and third in ACC's injury stats. Cycling and basketball round out the top five.

The number of claims per year and their cost to the taxpayer have ballooned in the past three years. Claims for rugby injuries have increased by almost 10,000, and the cost of treating them has risen from $13 million to more than $20 million.

"Overall, all ACC injuries are only going up by about 2 per cent a year, the same as the population," Simon Gianotti, ACC team leader, sport, said.

ACC had improved its systems for tracking data and reporting injuries, which Mr Gianotti believed was contributing to the rise in sports injuries.

However, because most people played sport socially there was no firm data on the number of injuries compared to the number of players - information which would pinpoint whether sport was becoming less safe or not.

"I regularly get asked what is driving the stats up and we can't pin it down to one factor. It could be a combination of them all."

Injury prevention programmes for the most popular sports are posted on the ACC website. Some sports, such as soccer, have devised a daily 10-minute exercise programme designed to minimise injuries, Mr Gianotti said.

Deb Hurdle, manager of Sparc's Push Play campaign, said there were mental and physical benefits to being physically active.

"Particularly at this time of year when people are under a lot of stress, whether it's financial or the fact that they're having to spend more time with relatives they may not necessarily get on that well with, being physically active is a really good opportunity to deal with those sorts of issues."

The benefits of exercise far outweighed its risks. But Ms Hurdle said people should still exercise caution.

"They should be reasonable about what they're trying to do.

"Rather than just deciding one day after having sat on the couch for three years that all of a sudden they're going to get out there and run a marathon, they need to start slowly and build up to it."

GOOD START NOT ALWAYS ENOUGH

Children who participate in sports during childhood are likely to remain active as adolescents or adults, but the link is weaker than popularly believed, a new study finds.

The Otago University study looked at around 1000 people's participation in sports groups at ages 7, 9, 15, 18 and 21, examining if those who were most active at early ages stayed the most active as they got older.

"We found that the stability of participation was only low to moderate, which meant that there was considerable movement into and out of sports," said lead author Dr Rose Richards.

"While children who participated in sport were twice as likely to participate during adolescence and adulthood, the strength of this relationship was much weaker than that suggested by the popular phrase 'active kids become active adults'."

Dr Richards said that while there remained a case for encouraging children to be active at an early age, it was dangerous to regard this as "inoculating" them against adult inactivity.

The paper was recently published in the US journal Research Quarterly for Exercise and Sport. The study followed 1000 Dunedin-born people since their birth in 1972-73.

- Errol Kiong