"It wouldn't be that everyone just gets off school early."
Christchurch secondary schools had previously given up Wednesday afternoons for sports, which had "worked quite well".
Giving schools more bats and balls without any real support or development did not lead to greater participation in sport, he said.
"What I get concerned about is kids that stop sport going from primary to secondary school, or when they leave secondary school."
Mr Mallard said clubs could get more involved with schools to keep kids active and engaged in sports for longer.
The policies would not cost any extra as a rejig of Sport and Recreation NZ would free some cash.
"They've got a weird dual-board system with the High Performance Board reporting to the main board, all under the same chief executive. To me, there seems to be no point in having something so complicated."
Labour would also ensure sports funding decisions were made by the Sparc board, not the minister, to prevent them from being politicised.
Extra funding could also come from partnerships with the private sector.
"Quite often you find organisations you can partner up with to get good value for money, and companies that want to associate their name with Sparc projects," Mr Mallard said.
The policy document also cites back-country huts and tracks as a significant asset that draws tourists.
"The existing network of back-country huts and tracks is vital as well and should remain. A bivvy in the right place, for example, can save lives," the document says.
"Labour will promote development of new outdoor recreational opportunities, for example, walking and cycling trails on former railways land."
Labour would also invest in training volunteers in coaching and management skills.
MAIN POINTS
* Nationwide study-free afternoons for pupils to play sports.
* Back-country huts and tracks are seen as a significant asset that draw tourists to New Zealand.
* Invest in upskilling volunteers - such as coaching and management skills.