WHY SUDOKU IS NOT FOR DIETERS

THE number’s up for puzzle fans...filling in a Sudoku grid or doing a crossword can be fattening.

Anyone who taxes their brain on word games uses up energy needed to exercise, according to a study.

It explains why some people feel exhausted doing a puzzle even though they have not got out of their chair.

The reason is that willpower is like a muscle and when it is used a lot for one task it may be too tired for another, Canadian researchers reported in the journal Psychology and Health.

Two groups of volunteers were sent for evening gym exercises for eight weeks but one were set a series of mental tests needing ­concentration by day.

They did not exercise as hard, said Professor Kathleen Martin Ginis. She added: “They were more likely to skip their exercise ­sessions. You only have so much willpower.”

But the good news is that you can build it up, such as by listening to music or taking a walk.

Sticking to tasks that require concentration also increases your stamina. The professor said: “Willpower is like a muscle. It needs to be ­challenged to build itself.”

Daily Express