Exact time of day to exercise to lower risk of heart disease, according to new research

 Exercising at a specific time of day could significantly lower your risk of heart disease, according to new findings. Researchers also found that when you work out could have an impact on your chances of developing diabetes, obesity, and high blood pressure.

Many of us are aware of the importance of exercise. The NHS recommends that adults take part in at least 150 minutes of physical activity a week due to the health benefits.

While the amount and type of exercise you do has an impact, the time you do it is also important. As part of this study, which is due to be presented at the American College of Cardiology’s Annual Scientific Session later this month, researchers analysed health data from almost 14,500 participants of the All of Us study.

This data included heart rate data from participants’ Fitbits, and exercise was assessed every 15 minutes throughout the day. The team then looked for links between the times of day participants exercised and cardiometabolic risk factors, such as high blood pressure, obesity, and type 2 diabetes.

Speaking to Medical News Today, the study’s senior author Prashant Rao said: “Cardiometabolic diseases remain the leading cause of morbidity and mortality worldwide. Even small improvements in risk at a population level can translate into substantial reductions in disease burden. Identifying modifiable behaviours, especially ones that are simple and scalable, remains a major public health priority,” he said.

Rao, who is a sports cardiologist and physician-scientist in the Division of Cardiovascular Medicine in Beth Israel Deaconess Medical Centre at Harvard Medical School, continued: “There is growing recognition that biology is not static across the day.

“Many important metabolic and cardiovascular processes follow circadian rhythms. Despite this, exercise recommendations have largely ignored timing. We wanted to test whether timing represents an independent and clinically relevant dimension of exercise behaviour in real-world populations.”

Researchers also evaluated participants’ rates of cardiovascular issues, such as coronary artery disease and atrial fibrillation. Overall, it was found that morning exercise lowered coronary artery disease risk by 31 per cent.

But more specifically, exercising between 7am and 8am was associated with the lowest odds of coronary artery disease, which is also known as coronary heart disease and is one of the biggest killers in the UK. Further to this, the team found that participants who exercised in the morning, when compared to those who exercised in the evening, were:

35 per cent less likely to have obesity

31 per cent lower chance of developing coronary artery disease

30 per cent lower risk for type 2 diabetes

21 per cent less likely to have high cholesterol

18 per cent lower chance of developing high blood pressure

“Importantly, these associations were independent of total physical activity, indicating that timing is not simply a proxy for ‘more exercise,’ but may reflect an additional behavioural or biological signal,” Rao said. “Exercise timing may represent a previously underappreciated dimension of exercise and cardiometabolic health. While any exercise is beneficial, morning exercise may confer additional advantages.”

He added: “The next step is to move from association to causation,” Rao added. “I think these findings should motivate a large randomised trial of exercise timing. Ultimately, the goal is to determine whether we can optimise exercise prescriptions not just by dose, but by timing.”

The results of the study are yet to be published in a peer-reviewed journal.

NHS advice

On the NHS website, it states that “being physically active” is one way to help prevent coronary heart disease. You can also lower the risk by:

Eating a healthy, balanced diet

Giving up smoking

Controlling blood cholesterol and sugar levels

In terms of physical activity, the NHS says adults should aim to:

Do strengthening activities that work all the major muscle groups (legs, hips, back, abdomen, chest, shoulders and arms) on at least two days a week

Do at least 150 minutes of moderate intensity activity a week or 75 minutes of vigorous intensity activity a week

Spread exercise evenly over four to five days a week, or every day

Reduce time spent sitting or lying down and break up long periods of not moving with some activity