London, Sept 3 : The time you spend working is the single most important factor that has an impact on your sleep, reveals a new study.

The study, by researchers at the University of Pennsylvania, was carried out on nearly 50,000 US participants.

The participants were questioned on three different occasions - in 2003, 2004 and 2005 - and asked how they spent their time between 4am the previous day and 4am that day.

The researchers found that the more hours people work, the less sleep they get.

Dr Mathias Basner, and his colleagues found that people who get less than four-and-a-half hours sleep a night worked an average of 93 minutes longer on weekdays and 118 minutes more at the weekend.

People who slept 11-and-a-half hours or more were found to work an average of 143 minutes less on weekdays and 71 minutes less on weekends.

The researchers also noted that short sleepers also spent more time socialising, studying and doing housework, reports the BBC.

Jessica Alexander from The Sleep Council said: "Survey after survey confirms that people are burning the candle at both ends more and more, with no let-up on increasingly global working environments that demand long working hours and 24/7 leisure opportunities.

"Modern technology has done nothing to free up our time and sleep length and quality is the victim.

"Eventually business, government and the medical profession will have to give sleep as much priority in their healthy living messages as diet and exercise - if not more.

"In the meantime, The Sleep Council will continue to spread the word and advise people how to improve their sleep quality, if not quantity, through simple lifestyle and environmental changes." (With Inputs from ANI)