Getting your workouts in earlier in the day, and sticking to a regular routine, could be a simple key to better heart and lung health as you get older.

A new study published in Medicine & Science in Sports and Exercise found that older adults who exercised consistently at the same time each day, especially earlier in the day, showed better cardiorespiratory fitness and walking efficiency. These are both important markers of healthy aging and a lower risk of chronic disease.

Researchers tracked about 800 adults with an average age of 76. Participants wore wrist monitors for a week to measure their daily activity patterns and underwent heart and lung fitness testing. The study revealed that those who were most active during the early part of their day had stronger cardiovascular health, even when the total amount of exercise was similar to others.

What made the biggest difference? Timing and consistency. Participants who had a regular daily routine, with activity peaking at the same time each day, had the best results. According to lead researcher Dr. Karyn Esser, “Being consistent with your activity pattern is an additional factor that likely contributes to better health.”

This research builds on the idea that our circadian rhythm, the body’s natural 24-hour clock, plays a role in more than just sleep. It also affects energy use, hormone levels, and how well we perform physical activity. Disruptions to this rhythm can raise the risk of heart disease, obesity, and other chronic conditions.

Esser explains that simply exercising isn’t always enough. “We suggest that the earlier time of activity and the repeatability of that activity provide benefits beyond the exercise itself,” she said.

The takeaway? If you want to improve your heart health as you age, don’t just focus on what you do, pay attention to when and how consistently you do it. Morning workouts and regular routines may help your body work better with your internal clock, leading to a longer and healthier life.