We know: practicing regular physical activity is one of the most effective ways to protect your heart. But a question often comes up, both among athletes and among people wishing to get back into it: should we favor the morning, the afternoon or the evening to maximize the cardiovascular benefits?
A recent study has rekindled the debate, suggesting that the time of day could also play a role in the prevention of certain chronic diseases.
A study which highlights the benefits of morning sport
Presented at the annual meeting of the American College of Cardiology, this study was based on a large sample of more than 14,000 participants. The researchers crossed their medical data with that recorded by connected watches such as Fitbit, in order to closely analyze their physical activity habits.
The observation is striking: people who practice physical activity in the morning, in particular between 7 a.m. and 8 a.m.present a significantly reduced risk of developing several cardiovascular and metabolic pathologies.
In detail, compared to those who train later in the day, they display:
- 31% lower risk of coronary heart disease;
- 18% lower risk of high blood pressure;
- 21% lower risk of hyperlipidemia;
- 30% lower risk of type 2 diabetes;
- 35% lower risk of obesity.
In other words, the morning window seems associated with an overall more favorable health profile.
Why morning could make a difference
How to explain these results? For Gérald Kierzek, several avenues exist, even if none alone constitutes a definitive explanation.
“There are times that are a little more favorable for the heart, but the key message remains simple: the best sport for your heart is above all the one that you do regularly, at the time that is possible for you.”
Among the hypotheses put forward, the role of the biological clock is central. Exercising in the morning would better synchronize sleep-wake rhythms and hormonal secretion, two essential elements for cardiovascular balance.
Another avenue: the metabolic effect. Morning physical activity improves insulin sensitivity and the management of sugars and fats in the blood. In the long term, this helps reduce the risk of diabetes, obesity and lipid disorders — all factors involved in heart disease.
Finally, the morning also acts as a behavioral lever.
“A session carried out early in the day plays a bit of a “shield” role: we are less exposed to unforeseen events, we reduce overall sedentary lifestyle and we often adopt a better lifestyle”, emphasizes Dr. Kierzek.
A moment to adapt according to your profile
However, morning exercise is not without precautions. When you wake up, the body naturally experiences a spike in blood pressure and cortisol.
“Now is not the time to force it brutally, especially in people with cardiac disease or a fragile heart”recalls Dr. Kierzek.
A gradual warm-up and a gentle increase in intensity are therefore essential, particularly for beginners or people at risk.
Moreover, other studies show that physical activity carried out in the afternoon or evening also provides significant benefits, particularly on overall mortality and cardiovascular risk.
“The most important factor remains regular practice, not the perfect time,” insists Dr. Kierzek.
For many, the evening remains the most realistic time to train, once professional and family constraints have passed.
The real message: move, no matter the time
In the end, if morning seems to offer a slight advantage, it should not become a hindrance. All scientific data converges on one essential point: physical activity is beneficial at any time of the day, even at low doses.
“Moving is beneficial at any time, and even small amounts of activity reduce mortality and cardiovascular events”recalls Dr. Kierzek.
The recommendations remain unchanged:
- At least 150 minutes of moderate activity per week (brisk walking, cycling, swimming, etc.);
- Or 75 minutes of more intense activity.
And as regularly as possible.
If morning exercise seems to offer a measurable advantage, experts remain categorical: the decisive factor remains regularity. Morning, afternoon or evening, the main thing is to move — because every minute of activity really counts to protect your heart in the long term.