But why not do both at once?
Tony Butlin, a former PE teacher turned consultant, has developed a series of physical activities teachers can use to improve pupils' literacy and numeracy.
These include doing sums while running through numbered archways, hitting golf balls on to letters to make words, and games of tag played by children wearing bibs with numbers in their pockets.
When learning about addition, a child with the number one might tag a number three, who would then have to find a number four.
It is a game that can be replicated for literacy, with pupils having to spell out words using the letters of children they have tagged. Mr Butlin is working with five Welsh primaries on a project paid for by Golf Development Wales, part of the Golf Federation. Each exercise in the Learning on the Move programme is explicitly linked to a national curriculum requirement.
Number bonds, part of the numeracy curriculum, are taught in a game in which two teams run around turning over plastic cones.
Ian Ashton, PE co-ordinator at Nottage primary in Porthcawl, Bridgend, south Wales, said the project has succeeded in making pupils more active and has improved their academic skills.
"Special needs children and those in Years 3 and 4 have found it brilliant.
It has made a big difference to their times tables and helped them identify consonants and vowels.
"The special needs class use it in most maths lessons and it is great in this weather for allowing children to spend more time outside."
Mr Butlin, former head of movement and health studies in the University of Sunderland school of education, worked unpaid with seven schools last year to develop his ideas.
Now he hopes to be able to implement them more widely.
"PE across England and Wales has been squeezed by literacy and numeracy. I really want a local authority to contact me and say we want to try this in our schools," he said.