 Summertime lifestyles typically mean less consistent sleep habits, and that can spell bad news for your heart health. Researchers have discovered that even with an adequate amount of sleep, individuals who went to bed 30 minutes past their regular bedtime had significantly higher heart rates while sleeping, and the elevated rates often carried through the next day. Surprisingly, even earlier than normal bedtimes had an adverse effect on heart rate. The lesson? An adequate amount of sleep is important, but so is consistency in our sleep routine.