DANVILLE - Now that daylight savings time is over, many may struggle to fall back into normal sleep-and-wake routines. While some relish the extra hour of sleep, others find the time change can significantly alter their internal clocks.

Although daylight saving time was instituted in an effort to save energy by capitalizing on natural light, the change in times of light and darkness also affects our circadian rhythm, a person's 24-hour natural body cycle. The human body is highly dependent on its circadian rhythm, which plays a role in sleep patterns, moods and even a person's ability to cope with stress.

"The most common affects we see as a result of the time change are variations in sleeping patterns and energy levels," said Dr. Alexander Villareal, sleep medicine specialist at Geisinger Medical Center. "The end of daylight saving time may cause people to experience a decrease in energy levels, a disturbance of the ability to concentrate in the afternoon and an increase in daytime sleepiness."

Most individuals adapt more quickly to the end of daylight saving time than the onset in spring, taking only a day or two to adjust their sleep patterns, Villareal said. However, there are still some who struggle with the decreased amount of daylight.

Villareal offers tips to help those who struggle with issues related to time changes:

- Exercise regularly, including long walks during the day

- Stay socially active with friends in order to stave off depression that can be brought on by the loss of daylight.

- Try light therapy with a special, bright fluorescent light that mimics sunlight in the early morning.

"I would recommend focusing less on the extra hour of sleep gained as daylight saving time ends in November and instead to use it as a reminder to ensure sleep is top priority," said Villareal. "The less you deviate from normal sleeping habits, the better you will be able to manage these biannual disturbances to your schedule."