Many people who study and/or work have to dedicate a specific time of the day to physical exercise due to a lack of free time. If this is not your case and you can choose exactly when to do cardiovascular activity, you should know that there is a better time to do it, although it depends on the objective you have in mind, as well as your circadian rhythms.
Before breakfast
If you've never exercised on an empty stomach before, you're likely to struggle to complete the routine in question, regardless of whether you're going to run, train at the gym, and so on. Still, it's well worth the effort if you're aiming to burn fat.
As you sleep you burn your reserves of glucose and other substances that provide energy. When you wake up you are at zero in this sense, so if you demand an effort from your body, it will be forced to consume other sources available to it, which in this case will be fat deposits.
Hunger may take its toll on you during the course of physical activity, especially if it is prolonged over time. To avoid getting half full because you can't resist the urge to eat, take a small bottle of water with you, which, although it's true that it won't satiate you, will give you extra hydration. This way you can complete your physical exercise and afterwards have breakfast.
Thanks to the release of serotonin that comes from doing a sporting activity, you'll feel a psychological high for the rest of the day. On the other hand, on a physical level, bear in mind that first thing in the morning your body is at a lower temperature. That's why there is a little more risk of injury, which you can prevent by stretching.
In the afternoon-evening
Generally speaking, most people experience an increase in hormone levels when the day has gone on for a few hours. Specifically, around 8 p.m. an optimum level is reached, which also refers to the temperature. The higher the body temperature, the lower the risk of injury.
However, if you have been working or doing any other minimally demanding work, it is likely that your energy reserve is not ideal for a sport that requires significant exertion.
It is for this reason that, if you do exercise in the evening, a low to moderate intensity is recommended. Otherwise, you will also be making a common mistake, which is to subject yourself to a high dose of adrenaline, which will later lead to sleeping difficulties.
The opposite is true if the sporting activity is not too demanding. The energy you have available will be more than enough to complete it and, in addition, it will give you a feeling of tiredness that a few hours later will result in conciliating sleep in record time.
Circadian rhythms
Although in most cases the aspects detailed above are met, they can vary depending on the individual. Every individual has circadian rhythms that differ from those of other subjects over the 24 hours of a full day.
Circadian rhythm changes are not only physical, but also mental, as well as behavioural. It is important to understand your own body in order to determine the best time to exercise, as the above may not be 100% accurate if your biological variables vary greatly from those of most people.