People might get more from their workouts if they time their exercise to their sleep schedule, a new study says.

“Early birds” and “night owls” who timed their exercise to when they were most alert wound up with lower blood pressure, blood sugar and “bad” LDL cholesterol levels, researchers reported April 14 in the journal Open Heart.

They also had better sleep quality, which might have contributed to these lowered heart risk factors, researchers said.

“Personalized, time-matched exercise interventions may become a practical strategy in clinical and public health settings, potentially leading to better outcomes and improved engagement,” concluded the research team led by Dr. Arsalan Tariq of the University of Lahore in Pakistan.

For the new study, researchers assessed the chronotypes – the natural disposition to morning or evening alertness – of 150 people between ages 40 and 60. All participants had at least one heart health risk factor.

People were then randomly assigned to exercise at a time that either matched their chronotype or didn’t – between either 8-11 a.m. or 6-9 p.m. They were asked to do five sessions of brisk walking a week for three months. 

In all, 134 people — 70 early birds and 64 night owls — completed all 60 exercise sessions.

Results showed that heart disease risk factors, aerobic fitness and sleep quality improved across the board.

However, matching exercise to a person’s chronotype produced larger improvements in blood pressure, heart rate, aerobic capacity, blood sugar, cholesterol and sleep quality, researchers found.

For example, systolic blood pressure fell by nearly 11 mm/Hg among people whose exercise sessions matched their chronotype, compared to less than 6 mm/HG for those with mismatched exercise sessions.

This reduction was even larger among those who started out with high blood pressure – nearly 14 mm/Hg for the matched group compared to 7 mm/Hg for the mismatched group.

“This study adds to a growing body of evidence suggesting that the timing of exercise when aligned with an individual’s internal biological clock can significantly enhance health outcomes,” researchers wrote.

Dr. Christopher Tanayan, a sports cardiologist with Northwell Lenox Hill Hospital in New York City, said this aligns with other research showing that matching exercise to your internal clock can improve blood sugar control.

These results likely reflect the greater efficiency the body can achieve when exercise matches its internal clock, Tanayan said.

“If you have a natural surge in hormones that support physical activity … in the morning that allows you to lift a heavier piece of weight or exercise for five more minutes (like run on a treadmill longer for five more minutes), because of the support of that hormone surge, then you're more efficient in overall,” he explained.

“So, you derive the larger benefits of exercise because you're able to do more exercise at that point in time,” Tanayan said.