SPOKANE, Wash. – The lost hour of sleep during Daylight Saving Time leaves most people feeling groggy. But researchers say "spring forward" could have more serious effects on your health.

A report in the American Journal of Cardiology found an increase in the amount of heart attacks the first week after the start of Daylight Savings Time. Researchers also found a similar pattern in Sweden.

In Canada, a study found more traffic accidents on the Monday after Daylight Saving Time than the Monday a week before the change.

Nobody knows for sure why losing an hour of sleep can cause these increases but health experts think the loss is just enough to disrupt the body’s internal body clock known as the circadian rhythm. This also controls hormone levels, overall health and alertness.

Doctors suggest an afternoon nap. While a single nap will not fully rest the body clock or make up for the lost hour, it can help you catch up and stay sharp. In fact, a former Boston University Professor proclaimed the Monday after the start of Daylight Savings Time as National Napping Day, an unofficial holiday.

The National Sleep Foundation says to find a dark, quiet and cool place for a 20 to 30-minute nap. A small amount of Japanese research suggests drinking coffee or tea before a nap, which could give the caffeine time to kick in and leave you feeling energized afterward.

While doctors are not sure about the caffeine approach, they do say naps can increase productivity at work and home.

If you do not have 20 to 30 minutes to close your eyes, just think about a nap. It can lower your blood pressure.