Click here for more articles by Kormedi.com.
A study has found that people who exercise in the morning tend to have a lower risk factor for cardiovascular diseases such as high blood pressure, type 2 diabetes and obesity, compared to those who exercise later in the day.
Researchers at Harvard Medical School and Beth Israel Deaconess Medical Center analyzed heart rate data collected over one year from wearable devices worn by approximately 15,000 adults.
They defined exercise as periods when heart rate remained elevated for at least 15 minutes, and classified participants according to the time of day they exercised. They then compared each group in terms of major cardiovascular risk factors, including high blood pressure, obesity, high cholesterol and coronary artery disease.
During analysis, they adjusted for various factors such as age, sex, income level, sleep, alcohol use, smoking and total exercise amount.
Key findings
Compared to those who exercised later in the day, the morning exercise group showed 35 percent lower risk of obesity, 31 percent lower risk of coronary artery disease and 30 percent lower risk of type 2 diabetes.
They were also 21 percent less likely to have high cholesterol and 18 percent less likely to have high blood pressure.
In particular, those who exercised between 7-8 a.m. had the lowest risk of coronary artery disease.
Why might morning exercise help?
Experts suggest several possible explanations.
First, it may be related to the body’s circadian rhythm. In the morning, levels of the stress hormone cortisol naturally rise, which may help prepare the body for activity. Exercise also acts as a stimulus that wakes up the body, so morning workouts may help increase activity levels and energy throughout the day.
Lifestyle differences may also play a role. Morning exercisers tend to maintain more regular routines. They are less likely to eat late meals or late-night snacks.
However, this was an observational study, meaning it cannot definitively prove that morning exercise directly improves cardiovascular health. Researchers noted that factors not fully accounted for — such as work schedules, socioeconomic conditions and lifestyle habits — may also have influenced the results.
Consistency is key
Should everyone exercise in the morning?
Experts emphasize that while timing can matter, the most important factor is consistency. If morning exercise is difficult, afternoon or evening workouts are still beneficial. However, if you have flexibility, morning exercise may be a good strategy because it’s easier to maintain consistency with fewer interruptions.
This article from Kormedi.com, Korea’s top health care and medical portal, is translated by a generative AI system and edited by The Korea Times.
