Researchers have confirmed that engaging in physical activity is generally far better for health than remaining sedentary. However, exercising early in the morning may provide an additional “treasure trove” of cardiovascular benefits.
In a study tracking 14,000 American volunteers and analysing heart rate data via Fitbit devices, scientists found that individuals who consistently exercised in the morning were 31% less likely to develop coronary artery disease compared with those who worked out later in the day.
The findings also indicated reductions in the risk of other health conditions for the same group: an 18% lower risk of high blood pressure, 21% lower risk of high cholesterol, 30% lower risk of type 2 diabetes, and 35% lower likelihood of obesity—regardless of the total daily amount of physical activity.
Specifically, exercising between 7:00 and 8:00 a.m. was linked to the lowest rates of coronary artery disease. The research team plans to present these results at the upcoming annual meeting of the American College of Cardiology in New Orleans this month.
This study is the first of its kind to evaluate both the amount and timing of exercise based on long-term use of wearable devices. However, the data do not confirm whether the relationship between exercise timing and cardiometabolic health is directly causal, or whether it is influenced by other factors.
The researchers highlighted that biological factors such as hormones, sleep quality, and genetics, alongside behavioural and psychological elements, could play a role in the observed benefits. They stressed that further research could help clarify these influences and provide precise recommendations for exercise timing.
“Previously, the focus was mainly on the amount or intensity of physical activity,” said Prem Patel, the study lead and a medical student at the University of Massachusetts Chan Medical School. “Now, with one in three Americans wearing a fitness device, we can monitor activity minute by minute, opening up entirely new avenues for analysis.”
