Working more than 40 hours a week 'makes you less productive', research suggests

A recent study found that people who work long hours are more likely to suffer a stroke

Ron Livingston in the film Office Space (Getty Images)

A game designer has posted a set of "Rules of Productivity", claiming that working over 40 hours makes you less productive rather than more.

Daniel Cook, whose professional online profile describes him as a game designer, pixel artist, toolmaker, physicist and MBA – and currently the Chief Creative Officer at Spry Fox – showed how working a 60 hour week could lead to a "productivity deficit".

He wrote: "In a 60 hour crunch people have a vague sense that they are doing worse, but never think that they should stop crunching. They imagine that working 40 hours a week will decrease their productivity. In fact, it will let them rest and increase their productivity".

Daniel Cook's suggestion of the contrasting levels of productivity according to hours worked per week (Daniel Cook)

Cook cited 31 studies which found flexible schedules "increased employee productivity and lower absenteeism", as well as a report by the National Work Life Measurement Project which claimed one third of managers

Cook’s rules were reposted by in a blog on LifeHacker, which reasoned: "If you’re a salaried employee who doesn’t get overtime pay, it’s basically like working for free."

A recent study found that people who work long hours are more likely to suffer a stroke, using results from over half a million subjects.

Published in the Lancet medical journal, the data showed the chance of a stroke increased beyond the traditional hours of 9am to 5pm. In comparison to a 35-40 hour week, working over 55 hours made a stroke 33 per cent more likely.

Researchers are still "at the early stages" of what is going on, with suggestions including the fact that sitting down for long periods is bad for health, and also that those who are chained to their desks have less time to eat healthily or exercise.

Dr Mika Kivimaki, from University College London, said: "Health professionals should be aware that working long hours is associated with a significantly increased risk of stroke, and perhaps also coronary heart disease."