WEDNESDAY, March 2 (HealthDay News) -- A daytime nap of at least 45 minutes may help stressed-out people lower their blood pressure and protect their heart, a new study suggests.

The finding comes from a study that involved 85 healthy university students, divided into two groups. One group had an hour-long period during the day to sleep, and the others had no time to sleep. Both groups were given a mental stress test.

Blood pressure and pulse rates increased in both groups of students when they took the stress test, but the average blood pressure of those who slept for at least 45 minutes was significantly lower after the stress test than it was for those who did not sleep.

"Our findings suggest that daytime sleep may offer cardiovascular benefit by accelerating cardiovascular recovery following mental stressors," wrote the researchers, Ryan Brindle and Sarah Conklin of Allegheny College in Meadville, Pa.

"Further research is needed to explore the mechanism by which daytime sleep is linked with cardiovascular health and to evaluate daytime sleep as a recuperative and protective practice, especially for individuals with known cardiovascular disease risk and those with suboptimal sleep quality," they added.

The study is being published in the International Journal of Behavioral Medicine.

On average, Americans get nearly two hours less sleep a night than they did 50 years ago, which could affect long-term health, according to background information in a journal news release on the study.

More information

The U.S. Centers for Disease Control and Prevention has more on sufficient sleep.