Study with sedentary adults associates training at the chronotype time with gains in heart, metabolism and sleep
Is there an ideal time to exercise? A new study suggests so. Published in April in the scientific journal Open Heartthe work observed more significant benefits for the heart, metabolism, physical conditioning and sleep quality when participants practiced physical activity at times compatible with each person’s biological clock.
In the research, 150 sedentary adults aged 40 to 60 were followed for 12 weeks. Divided according to chronotype (morning or afternoon), participants performed exercises at times aligned or opposite to the body’s natural functioning. Those who trained in tune with their biological clock showed a more pronounced improvement in cardiovascular and metabolic indicators, in addition to gains in physical fitness and sleep.
And that makes sense in clinical terms. “It’s not just a personal preference. There is a biological clock that regulates, throughout the 24 hours, when blood pressure rises, when the metabolism is most active and when the body responds best to physical effort”says cardiologist Israel Guilharde Maynarde, from Einstein Hospital Israelita in Goiânia. “Those who wake up early spontaneously and already feel ready tend to be morning people. Those who perform better at night, and naturally sleep and wake up later, tend to be evening people”.
According to the cardiologist, knowing this difference in chronotype is important, because the body does not function in the same way throughout the day: blood pressure, heart rate, body temperature, metabolism and hormonal response follow natural fluctuations, controlled by the circadian rhythm.
Among the hypertensive participants in the study, those who trained at times compatible with their chronotype showed an improvement in systolic blood pressure, the measurement when the heart contracts to pump blood. When it is high, it increases the risk of heart attack, stroke, heart failure and kidney disease. “This was already a topic discussed in previous studies, but this work reinforces the importance of aligning training time and the biological clock”said Maynarde.
However, this does not mean that there is a “perfect and universal time” to train. The article itself shows that even participants who exercised at times considered “out of alignment” with their chronotype also improved cardiovascular and metabolic indicators, albeit in a more discreet way. “Exercise continues to be beneficial regardless of the time of day. Alignment seems to work as an additional gain, not as a mandatory condition for results”says the cardiologist.
These findings also help to debunk the myth that doing physical activity in the morning would increase the risk of heart attack. Although cardiovascular events are more frequent in the early hours of the day, this does not mean that morning exercise is dangerous for those who practice physical activity regularly.
“The greatest risk tends to be in sedentary people, with decompensated cardiovascular disease, who exert intense effort abruptly”declares Einstein’s doctor. “For those who train regularly, with adequate progression and warm-up, morning exercise is safe and, in morning individuals, it may even be the period of best physiological response”complete.
The study also found a significant improvement in sleep quality among participants who trained at times compatible with their chronotype. It makes sense, since physical exercise also acts as a biological clock synchronizer. “Exposure to natural light in the morning, regular sleeping and eating times, and maintaining a consistent exercise routine help adjust your circadian rhythm.”says Israel Maynarde.
This text was originally published by Agência Einstein, on June 13, 2026. The content is free for republication, citing the source, and was adapted to the standard of Poder360.
