Ministers have hailed an "extraordinary turnaround" in school sports as an official survey found the Government had hit its physical education target a year early.
An aim to ensure 85% of youngsters get two hours of PE every week by 2008 has been met, according to the 2006/7 School Sport Survey.
It follows £2.3 billion of investment over the last 10 years. Prime Minister Gordon Brown announced a further £100 million this year to try to raise the hours of school sport available each week to five.
Focus on school sports comes as ministers are drawing up plans to tackle rising levels of obesity.
A new Government study warns of an impending crisis in public health, which Health Secretary Alan Johnson described as on the same scale as climate change.
Some 86% of men are expected to be overweight within 15 years and 70% of women within 20 years, Professor Klim McPherson of Oxford University and Tim Marsh of the National Heart Foundation predict.
Schools Secretary Ed Balls said there was now a need to concentrate on those children who were not taking advantage of the sports opportunities on offer.
"We know that girls, especially as they get older, often stop taking part in sport," he said.
"But there are some excellent examples around the country like a sports college in Warrington which runs evening fitness classes specifically for mums and daughters."
Mr Balls said out-of-school activities and parents' involvement mattered most. "There's a role for schools in showing leadership," he said. "But it's what parents and kids do at home and after school which matters most."
