People who stay active late at night, often called night owls, may have a higher risk of heart problems, a new study suggests. Researchers say the mismatch between the body’s internal clock and daily routines can affect heart health, but lifestyle changes can reduce the risk.

The study, led by Sina Kianersi of Brigham and Women’s Hospital and Harvard Medical School, tracked over 300,000 adults in the UK Biobank for 14 years. About 8% identified as night owls, while a quarter were early birds and the rest had typical sleep patterns. Night owls were found to have a 16% higher risk of a first heart attack or stroke compared to the average population. Women night owls showed especially poorer cardiovascular health.

Experts link the risk to behaviors like smoking, poor diet, insufficient sleep, and less physical activity. “Night owls are not doomed. The challenge is living in a morning person’s world,” Kianersi said. The misalignment can affect metabolism, blood pressure, and other heart-related functions.

The American Heart Association recommends eight key habits for heart health: regular physical activity, avoiding tobacco, getting enough sleep, healthy diet, and controlling blood pressure, cholesterol, blood sugar, and weight. Researchers say night owls can follow these steps to protect their hearts, even if they prefer late-night schedules.

Experts also suggest sticking to consistent sleep and wake times and focusing on quitting smoking as a priority. “Focus on the basics, not perfection,” Kianersi said.

The study highlights the importance of aligning daily habits with the body’s natural rhythm while maintaining heart-healthy behaviors.