Night work (1) has existed for a long time in professions such as the police, firefighters, health etc. However, with the era of industrialization, the number of employees on staggered hours or at night (2) is increasing. The law of May 9, 2001 authorizing night work for women in industry has only accentuated this phenomenon. Today, 15.2% of workers are affected. And among them, about 60% complain of chronic insomnia, compared to 22% of French people in general.
Sleep disorders and the quality of life of these people remain a concern. The average sleep debt is estimated at one night per week, or around 50 nights per year.
De facto shift workers (3) are often subject to desynchronization with phase advances or delays. The biological clock will actually require 2 to 3 days to re-adapt the sleep/wake cycle following a change in schedules or after the rest period. The internal temperature will require around 8 days to reset.
In addition, the body will resist to hold on to times when it is supposed to sleep. For example, the period between 2 a.m. and 4 a.m. is particularly difficult since the body is slowing down:drop in internal temperature, slowing of breathing, heart rate, strong presence of melatonin, the sleep hormone, drop cortisol. It is also the time of optimum cell renewal with the production of growth hormone which repairs the tissues.
In addition to more frequent repercussions on his health such as cardiovascular alterations, immune or digestive disorders, increased risk of obesity and diabetes, chronic fatigue, mood disorders, an impact on cognitive abilities, the predominance of certain cancers (that of the breast in women and that of the prostate in men), the shift worker often struggles against drowsiness.
Chronic lack of sleep frequently induces phases of drowsiness. Blurred vision, a diminished visual field, altered reactivity times, slower decision-making:all these factors increase the risk of accidents at work and/or road accidents.
You should know that:
No, nothing stops the pressure of sleep except stopping to sleep, even if only for a few minutes!
The lifestyle of the worker with atypical hours
Working atypical hours requires more restrictive sleep hygiene and life balance. But neglecting your sleep is neglecting your health. In fact, the lifestyle of the shift or night worker is very similar to that of the competitive athlete with its rules and requirements:
Note:the jet-lag , which particularly concerns people who travel abroad for their work, with the passage of at least 3 time zones, causes disorders similar to those of shift work.
(1) Remember that night work involves a minimum of working hours between 9 p.m. and 6 a.m. (possibly pushed back to 7 a.m. with the new Labor Law).
(2) Night work and shift work are so-called "atypical" schedules and which can, by their specificities, cause health risks. "Atypical working hours" are defined as all arrangements of working time that are not "standard" . Standard work corresponds to the following configurations:5 regular days per week from Monday to Friday, working hours between 5 am and 11 pm, with 2 days off per week.”
For more information:National Research and Safety Institute for the Prevention of Workplace Accidents and Occupational Diseases (INRS)
(3) Shift work:any mode of organization of team work according to which workers are occupied successively on the same workstations, according to a certain rhythm, including rotational rhythm, and which may be of the continuous or discontinuous type, resulting in workers having to perform work at different times over a given period of days or weeks