You regularly do sports but maybe at the wrong times. That may be the problem. A new study suggests that exercising at the right time, aligned with your internal biological clock, significantly enhances the cardiovascular benefits of exercise. The difference is striking.
Sport Chronotype and Cardiovascular Health: What the Study Measured
Arsalan Tariq and colleagues published the results of a randomized trial among 150 adults aged 40 to 60 in public hospitals in Lahore, Pakistan, all with at least one cardiovascular risk factor. Volunteers were randomly assigned to exercise sessions synchronized or not with their natural profile. 134 people completed the entire program.
The protocol was the same for everyone: 40 minutes of brisk walking on a treadmill, five times a week, for 12 weeks. Early risers exercised between 8 am and 11 am, while night owls exercised between 6 pm and 9 pm. Those whose schedule matched their chronotype had significantly better results. Systolic blood pressure decreased by 10.8 mmHg in the corresponding group compared to 5.5 mmHg in the non-corresponding group. For hypertensive individuals, the difference was even more pronounced, with -13.6 mmHg versus -7.1 mmHg.
Why Aligning Chronotype and Exercise Also Improves Sleep
Sleep quality improved by 3.4 points in the corresponding group compared to 1.2 points in the non-corresponding group. Aerobic capacity, heart rate variability, and metabolic markers such as fasting glucose and LDL cholesterol also showed greater improvements in aligned volunteers. All improved, but those whose schedule matched their biology improved more.
How This Study Changes Cardiovascular Prevention Exercise Prescriptions
Dr. Rajiv Sankaranarayanan of the British Cardiovascular Society believes that these results offer a pathway for preventive cardiology, particularly in public health systems like the NHS in the UK. Integrating a simple assessment of chronotype into exercise prescriptions could improve adherence and outcomes for hypertensive or cardiometabolic patients.
However, the authors acknowledge significant limitations. The study only included volunteers recruited in Lahore and excluded intermediate chronotypes, restricting its generalizability. Additionally, post-intervention tests were conducted only three days after the program ended. Long-term results need further documentation before considering systematic integration of chronotype into public exercise recommendations.
