Playing the numbers game: Why too much sudoku could ruin your figure

Sudoku puzzles might give your brain a good workout but they could add inches to your waistline. 

Anyone who taxes their brain on the number grid, as well as taking on crosswords and other word games, could be using up energy needed to exercise, psychologists claim.

This might explain why some people feel physically exhausted after a puzzle even though they have not even needed to get out of their chair.

Playing too many puzzles such as sudoku could use up the energy needed for exercise

Good for the brain, bad for the waistline: Playing too many puzzles such as sudoku could use up the energy needed for exercise

Researchers for the scientific journal Psychology and Health said tests found that people given puzzles and exercise sessions performed less well than people who just exercised. They concluded that time spent on puzzles drained willpower. 

Willpower is needed to concentrate on the clues or numbers for a brain-teasing puzzle but also to drag a reluctant body down to the gym.

A hard day at work can have the same effect and many will recognise the feeling of coming in after a day at the office and feeling too tired to do anything else that evening. 

Canadian professor Kathleen Martin Ginis said: 'Cognitive tasks, as well as tasks such as regulating your emotions, can deplete your self-regulatory capacity to exercise. 

'Willpower is like a muscle  -  it needs to be challenged to build itself.'
Sticking to a task that requires willpower, whether it is going without chocolate or doing homework, actually strengthens it. 

There are ways to build up the 'willpower muscle' after a hard day at work or particularly difficult sudoku, such as listening to music or simply going for an evening walk. 

Professor Martin Ginis also said the results should not be used as an excuse for lazy but brainy couch potatoes to avoid exercise.

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