(Agencies)
Updated: 2008-03-04 16:58

NEW YORK -- Steve Nichols, a middle manager at a technology company in Ohio, gets home late from work and spends most evenings sending work-related e-mails.

Like many other Americans he is working more and sleeping less which could have an impact on their professional and personal lives.

A new survey by the National Sleep Foundation shows people are spending an average of 4.5 hours each week doing additional work from home, on top of a 9.5 hour average work day.

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While 28 percent of people questioned in the survey said their daytime sleepiness interferes with their daily activities at least a few days a month, 63 percent said they are likely to accept their sleepiness and keep going.

"There's enough data now to clearly show that if you're not sleeping enough, that's going to dramatically affect your performance and productivity," said Mark Rosekind, a former director of the Center for Human Sleep Research at the Stanford University Sleep Center who helped design the poll.

"People think if I can jam more hours in the day I'll get more done. That's not true," he added in an interview.

Although Nichols, 35, said he hasn't noticed any negative effects, his wife says he looks beat up and run down. The only time he catches up on his sleep is when he takes a vacation where his BlackBerry doesn't work.

"That removes the temptation," he said.

Nearly one third of the 1,000 people who took part in the telephone poll late last year said they fell asleep or were tired on the job in the past month, and 12 percent reported being late to work.

Rosekind said estimates of what an overtired workforce costs the economy have put it at between $50 and $130 billion each year due to lost job productivity, accidents, injuries and medical conditions.

He added that most people will rate themselves as being wide awake and performing at a good level but "when you measure them they're horrible."

The poll also showed that lack of sleep is affecting people's safety. Nearly 40 percent of people report nodding off or falling asleep while driving and 14 percent missed family events, work functions and leisure activities.

Almost one in four of those questioned admitted doing job-related work in the hour before going to bed at least a few nights each week, so it's no surprise that 20 percent are having less sex because they are too tired.

Victoria Castillo would like to be able to turn her brain off from work. The 33-year-old artist spends between 60-70 hours each week in her home-based studio in College Station, Texas, and like almost one in five of those surveyed, uses an over-the-counter sleep aid at least a few nights each week.

"It does take a physical toll and a mental toll and a toll on my work when I can't sleep. They do feed each other. If I could change one thing in my life it would be to be able to sleep," she said.