The early bird gets the worm, right? Well, according to new research, those early birds could be causing themselves heart problems.

Researchers in various hospitals and universities in Kyoto, Japan found the worst time a person can wake up is before 5 a.m. They found that those who rise before 5 a.m. have a  1.7 times greater risk for high blood pressure and are more likely to develop hardening of the arteries.

The best time to wake up? Researchers say people should sleep-in until at least 7 a.m. or 8 a.m. every day.