The "bouts of fatigue" of a working day correspond to natural phases of drop in concentration that can be anticipated, according to doctor Jimmy Mohamed, health consultant for Europe 1. It is possible in particular to target certain time slots during which we are more active.

We all know these moments of low energy, synonymous with lower concentration, and therefore reduced efficiency at work.

But did you know that it is possible to anticipate them?

This variation in vigilance has a physiological explanation: we are naturally programmed to be active or tired at specific times.

A fundamental rhythm that we gain by listening, according to doctor Jimmy Mohamed, health consultant of Europe 1. 

A link with body temperature

To create a curve of vigilance according to the day, a first way is to compare it to ... your body temperature. When this rises, your body prepares to be in an active phase - that is, to be awake and efficient. And conversely, when your temperature drops, your vigilance does not take long to decrease.

More generally, concentration peaks correspond to hours, the same for everyone, and which do not necessarily "stick" with our habits.

Between 9 a.m. and 11:30 a.m., we are in an active phase: for adults, it is the ideal time to be productive and for children, the time to learn new things.

Between noon and 2 p.m., we have all experienced it, we are in a phase of withdrawal, tired and less efficient physically.

So that's when kids should take a nap. 

>> Find Jimmy Mohamed's column every morning at 8:37 am on Europe 1 as well as in replay and podcast here

The rest of the day is interesting: we keep on seeing that between 5 p.m. and 8 p.m., we are in a new phase of vigilance, with excellent physical and intellectual performance.

As we know, children are often excited about this time slot.

But it's actually a great time to study and learn really fast.

Vigilance at its lowest between 11 p.m. and 5 a.m.

And then, naturally, between 11 p.m. and 5 a.m., we are in a phase of fatigue, of low vigilance. The critical point is reached between 2 and 5 in the morning: it is the niche on which occur many car accidents, or even tragedies like that of the American nuclear power station of Three Mile Island, which was carried away with 3 o'clock in the morning, in 1979. At that time, the engineers and technicians on site, whose concentration was at its lowest, had not succeeded in making the necessary decisions.