Children should be tested for fitness, as well as maths and English, to reduce inactivity, say health campaigners.
Campaign group ukactive says the UK faces a "ticking time bomb" of health problems due to lack of exercise.
Its report says only half of seven-year-olds in England are active for an hour a day, and says more activity should take place in the classroom.
The government says it has increased funding for PE, and that primary schools offer two hours of it per week.
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