July 24 (HealthDay News) -- Bad bedtime habits can keep you up at night and cause problems during the day, says the head of a Texas sleep study facility.

Stress, worry, caffeine, alcohol and watching TV in bed -- factors known as "poor sleep hygiene" -- are the major reasons why people can't shut down their bodies when it's time for sleep, explained Dr. Sunil Mathews, medical director of the Sleep Center at Baylor Medical Center at Irving, Texas. Poor sleep hygiene can also lead to taking sleep-aid medications that could interfere with alertness the next day, he said.

A recent National Sleep Foundation poll found that 47 percent of people with sleep problems were likely to use caffeinated beverages to compensate for their daytime sleepiness, but these stimulants contribute to more difficulties sleeping.

"Insomnia can turn into a vicious cycle," he said in a news release from the medical center.

To develop good sleep hygiene, Mathews recommends the following:

• Develop a calming bedtime routine. Relax body and mind through yoga, biofeedback and meditation, or take a cup of warm milk with nutmeg.
• Avoid workouts within four hours of bedtime. While regular exercise relieves stress, it also raises core body temperature, which can make falling asleep more difficult.
• Avoid caffeine, alcohol or sugary items within eight hours of bedtime.
• Keep your bedroom dark, cool, quiet and comfortable.
• Maintain a regular sleep schedule, even on weekends.
• Use your bedroom for sleep only. Find someplace else to watch TV, plan your day or fret so that your mind associates the room only with sleep.

SOURCE: Baylor Medical Center, news release, July 20, 2009