NINE out of 10 teachers fear children are missing out on learning vital skills because they are not playing enough sport outside school, says a survey today.
Pressure to get top results in school tests - and exhausted parents - are among factors holding children back from taking more exercise, the report suggested.
Pollsters YouGov found that 81% of teachers believe sport actively helps children concentrate.
Some 64% said youngsters who play games in their free time are more confident and participate better in class.
Half the teachers questioned said it was as important for children to focus on sport as on study.
Three-quarters of children interviewed told the researchers they would like to play more sport with their parents.
Some 55% said they preferred playing with their parents as they did not have to worry about making mistakes.
But 25% of parents admitted never playing sport with their children if they could avoid it.
The report's author, Prof Richard Bailey said parents were struggling to strike a balance between work and play.