For some office workers, the greatest productivity killer is the Internet, including non-work-related e-mail, social networking and mindless Web surfing. For others, it's particularly chatty co-workers who won't give you a moment's peace. 

For many, however, the problem all boils down to lack of sleep in your off time, causing you to space out for long periods of time, have difficulty concentrating on a task, and sometimes even nod off on the job. Not getting enough sleep is one of those few instances when your behavior outside the office affects your productivity inside the office. 

According to the National Sleep Foundation, sleep deprivation is linked not only to various health and behavior problems, but it is also linked to decreased productivity.

In fact, a 2008 survey by the Foundation revealed that 29 percent of survey respondents fell asleep or became very sleepy at work in the past month; 12 percent of respondents reported being late for work in the past month due to sleepiness or a sleep problem. 

So why aren't some of us getting enough sleep? The Foundation maintains that it is a common myth that a person needs less sleep the older they get. The average adult actually still needs between 7 and 9 hours of sleep. Another myth is that you can get more done the less you sleep. The truth is that you actually have an increased capability to learn and retain new information after you've had a full night's sleep. 

Even more telling is that surveys by the Better Sleep Council have also shown that lack of sleep can have a negative effect on the quality and accuracy of your work; on your clear thinking and judgment; and on your memory of important details, all of which directly affect your office productivity. 

So what are some practical ways we can get a better night's sleep? Consider the following: 

*Don't bring a television or laptop into your bedroom. You need to associate your bedroom with calm and quiet, not with wakeful activities like work, entertainment and social networking.

*Do some research and purchase a better quality mattress. It's hard to buckle down and buy a good mattress, especially when you already have one, but it's something you should really think about investing in if you care about getting a better night's sleep.

*Avoid caffeine and sugary foods/drinks late at night. These have been proven to mess with a person's sleep patterns.

*Go to bed at the same time every night, if possible. Your circadian rhythm is dependent on it.