Holidays: “It takes more than ten days for the change of pace to have a real effect”

Professor at the University of Caen and director of the COMETE research unit within Inserm, Damien Davenne specializes in the study of the biological rhythms of living beings. Between his keys to recovering during the holidays and his advice for optimizing his holidays over the year, the chronobiologist is categorical: any phase of activity must be followed by a period of rest. He tells us why?

After how many days of vacation do we really pick up?

Usually you’re in the coaltar the first few days of vacation, but it depends a lot on what state you’re in when you leave. I think it only takes two to three days to really let go and immerse yourself in vacation if you have a profession that allows it. It may take up to five days for people who really need to get back to normal nights of sleep, at their own pace. There are also people for whom work is quite bearable, who don’t like to slow down and manage never to do so: they don’t change their habits by going on vacation.

It remains very individually dependent: everyone has the ability to let go or not. It varies according to what you let go of and the stress you had just before leaving: often, the fact of leaving leads to a stressful week because you have a lot of things to finish and you don’t have time for the make. This is where you have to know how to let go. In addition, some people need two to three days at home to take a break before leaving, while others will absolutely have to leave immediately because they do not feel on vacation at home.

How long do you have to leave to feel the positive effects of the holidays?

It takes more than ten days for the change of pace to have a real effect and for you to really benefit from it. This is why the ideal is to organize your vacation in slices of two weeks, at least. Long weekends can also be effective because they are not long enough for the change of pace to take place. Conversely, one-week vacations like those of All Saints’ Day are an aberration: they are both too long and too short.

How to recover well on vacation?

Regularity is key, even if we’re partying because we’re on vacation. By setting extremely regular waking times, everything else will follow: we will go to bed at the right time the night before, when we can do so. It is necessary to sound out: if you are in the morning, it is advisable to wake up between 6 and 7 am, and if you are rather a night owl, it is better to aim for an alarm clock around 9 or 10 am. Of course, leaving a margin of one hour is far from catastrophic. Finally, when possible, it is recommended to establish a daily nap of 20 minutes, maximum.

If you ignore your own rhythms, you mess up your system and you waste a lot of energy for nothing. Thus, it is also necessary to apply the regularity of the sleep/wake rhythm to meals, avoiding too much excess in the evening. Recovering also involves exerting yourself, and entering into phases of meditative rest, with very beautiful landscapes before your eyes, for example. In short, we really have to avoid stressful situations, let go and taste life, what is offered to us; simple pleasures.

What is the right annual vacation frequency to adopt?

The only work that has really been carried out relates to the field of education. We know that, in this environment, there are seven weeks of activity then two of rest in the optimal periods. It is the ideal. On the other hand, having introduced long summer holidays is not, because it is the time of the year when we are programmed to be more active, more dynamic, more ‘profitable’. It is also paradoxical for children, since it is there that they are the most receptive and efficient for learning.

We should rather sleep longer and rest in winter, but, even if everything favors it, that’s not how we manage our lives. Then, it must be said that it is not unpleasant to have a vacation in the summer because you can go to the beach and visit extraordinary places thanks to the weather conditions. Moreover, there is a whole individual and collective economy that encourages people to go out and consume in the summer: this is perfectly accepted.

Should we “get rid of” the limit of five weeks of leave per year?

It’s quite complicated. This would amount to a reduction in working time. A whole societal philosophy was engaged with the 35 hours, and this quickly derived with mechanisms at the level of individual organization, often at odds with the person’s physiology. For example, for many, 35 hours amount to 3.5 days of work: it is an aberration. In reality, there should be little daily work, spread over many days. We are not made for certain types of jobs that require a lot of work, but the lure of profit comes into play, as well as many other considerations that make us forget the physiology of the individual.

Despite everything, we must keep in mind that we need rest: any phase of activity must be followed by a period of rest, otherwise the rhythm sets in to the detriment of the individual. This is what we find at the level of the sleep/wake indicator: we can work on losing sleep and, very often, vacations make it possible to recover the latter. Thus, many insomniacs sleep a little better on vacation.