How exactly do rotating layers work

Shift work and health - the practical guide for healthy shift work

Shift work and health - Promote healthy shift work

One of the requirements of today's working world is to react flexibly and be mobile. In many industries, immediate reaction to customer requests and continuous competitiveness require work around the clock. This has long been indispensable in a number of professions, so we no longer want to do without continuous work processes in medical care and in many other service sectors. Even in the manufacturing industry, working in shifts has long been indispensable. The growth of the service sector and the growing desire for flexibility in the 21st century have brought about a drastic increase in the number of shift workers. So it happened that in 2011 around 17 million people in employment in Germany worked in a rotating shift system, 2.5 million of them on night shifts (600,000 women and 1.9 million men, see source 1)



Shift work is not only exhausting, but also harmful to health

Studies show that shift work is particularly demanding on workers. There are differences in the physiological workload in late and night shifts. The objective load increases with the same activity in the different shifts:

  • In the morning shift: 100%
  • In the late shift: 113%
  • During the night shift: 156%

The reason for this is the work against the "internal clock": We work in shifts against the biological rhythm of the human body. Most of the biological and psychological processes in our body follow a natural rhythm. Many body functions have a cycle of about a day's length and are known as circadian rhythms. For example, blood pressure, pulse, breathing, body temperature and digestion are linked to the internal clock. External timers such as daylight are responsible for ensuring that the "internal clock" is based on the day-night rhythm.

Since humans are by nature diurnal, we are particularly productive during the day and especially in the morning. Then all body functions go down during the night. The body is programmed to rest, which means that we are less concentrated and less productive.

The result of the additional workload in late and night shifts is increased error rates. Chernobyl, Exxon Valdez, Three Miles Island or the Costa Concordia disaster - all four disasters occurred in the late and night shift.

Health risks are also associated with shift work: If we continuously work against our internal clock, the body is exposed to continuous stress. Disorders of the bio and sleep rhythm are the result, which have physical and psychological consequences: sleep disorders, loss of appetite, stomach problems, inner restlessness and nervousness as well as tiredness and fatigue are some of the typical symptoms that workers who have to work shift work suffer from. The changed daily routines due to shift work also often have an impact on social and private life.


The health effects depend on certain factors. How regularly can meals be taken? Can you sleep until at least 6:30 a.m. in the morning? Is the work finished by 8:00 p.m. at the latest? The temperatures and light conditions at work can also influence a person's motivation and constitution. The following symptoms or diseases can occur as a result:

• Disturbance of the biological day and night rhythm
• Type 2 diabetes
• Cardiovascular diseases
• Problems with digestion
• Deficiency in vitamin D (deficient exposure to sunlight)
• Depressions
• Eating disorder
• nervousness
• Fatigue
• stomach discomfort
• Sleep disorders

The shift workers are particularly troubled by sleep disorders. There is also an increased risk of accidents, which can lead to injuries or serious damage. There are plenty of examples of this. The reactor accident in Chernobyl, the crashed oil tanker Exxon Valdez, the damage on the Costa Concordia with subsequent accident, as well as the core meltdown at the Three Mile Island power plant in Pennsylvania occurred during the late or night shift.

Healthy in shift work - Strengthening the physical and mental health of shift workers

How the “internal clock” dictates our life

People get hungry at a certain time, they get tired and have an inner rhythm. All of these biological patterns are very strong and are linked to brightness and temperature. These ensure the control of a balanced bio-rhythm in the human body. Shift work can mess this up.

In particular, problems with the gastrointestinal tract and sleep disorders, which often become chronic ailments, are the result. Both areas of the disease can be traced back to the unsteady rhythm of the body. Life is led against the rhythm of the "internal clock". Contrary to all assumptions, the body cannot permanently adapt to this schedule. The shift change with its regularly changing working hours is not suitable for this. Employees report that colleagues who have to leave shift work for health reasons, for example, look up to 10 years younger just a few months later. So there is a need for action.

There are people who achieve their greatest motivation in the morning and others who work most effectively in the afternoon or evening. It is not for nothing that morning people and morning grouch or larks and owls are often spoken of. What is noticeable here is that nobody experiences their most productive phase at night.


How exactly does the “internal clock” tick? - Physical reactions


6 o'clock - The body begins to take in more oxygen. Accelerate blood pressure and heartbeat. The muscles are better supplied with blood. The body says: get up!

9 clock - The cycle is in full swing. This also applies to human performance. This is 40% above the daily average.

12 o'clock - More stomach acid is produced for two hours. This means that it is the perfect time of day to get something to eat. Afterwards digestion is busy. This has a negative effect on work efficiency. This time is, for example, the perfect time for a break.

14 o'clock - This is where the next high of the day begins, which can last up to 8 p.m. However, with a 10% increase in performance, it cannot be compared with the increased work performance in the early morning.

8 p.m. - Blood pressure drops, breathing slows down, the body demands rest. At this time at the latest, from a biological point of view, it would be time to end work.

22 O `clock - The body functions are further regulated downwards by the body. The performance continues to fall below the daily average. Therefore, the regular time to fall asleep with a normal daily rhythm should also fall between 10 p.m. and midnight.

3 o'clock - The body functions are reduced to a minimum. The frequency of the heartbeat is only half that of the day. This also applies to shift workers on the night shift. It makes no difference whether we are awake or asleep, because the body is now in sleep mode.

6 o'clock - The next day begins.

Most employees rate the performance in the early shift as the best. This also corresponds to the biological performance curve. During the night shift, productivity drops to a minimum.


More and more difficulties for shift workers from the age of 50

Shift workers' productivity changes in the second half of life. From the age of 50, the ability to regenerate decreases on average, increasing sleep disorders and gastrointestinal diseases are reported. Physical work is not only subjectively more difficult in old age, it is also objectively. The older worker does more physiologically on a night shift than he did in his younger years; the workload increases beyond the already mentioned 156 percent.


Shift work until retirement at 67 - is that possible?

In Germany, the average age of the workforce is increasing due to demographic change. Therefore the question arises: "Shift work up to retirement 67 - how is that supposed to work?"

In order to counteract the shift-specific problems and to make the employee fit for shift work, it is important to take measures to avoid illness in good time. Employers and employees have various means at their disposal that can help ensure that employees in shift work remain healthy and productive until they retire at 67.


Measures to promote the health of shift workers

Despite the negative effects, shift work is irreplaceable in many industries. Doctors and nursing staff cannot stop working at night. The costs in various industries would be immensely high if, for example, production lines had to be stopped or work processes interrupted. The effects of shift work cannot be completely eliminated, but they can definitely be influenced positively.


Measures to improve the effects of shift work:

  1. Positive thinking

This principle seems banal. In a study with police officers it was scientifically proven (Schweflinghaus, 1990) that officers with a positive attitude towards shift work had fewer gastrointestinal complaints and had less disturbed sleep after the night shift. Anyone who identifies with shift work and is not constantly in a bad mood therefore has to struggle with fewer effects.


2. Workplace health promotion for shift workers

It is the employer's task to create health-promoting framework conditions in order to relieve the shift worker. One of the most important instruments for this is the Working Hours Act, which regulates the organization of break times, weekend shifts and working hours in general. This provides for a regeneration phase of 11 hours between two shifts, for example. The employer should provide suitable relaxation rooms and encourage his employees to take breaks efficiently. In addition, the employer is obliged to undertake occupational health check-ups for shift workers every 3 years. For employees over 50, this even applies once a year. The company's job is to communicate this possibility and to motivate employees to investigate. Job rotation systems for distributing the load and training young junior employees are further steps that employers can take to relieve shift workers, especially in old age.


3. Ergonomic layer systems

The introduction of an ergonomic shift system by the employer is generally necessary. An ergonomic shift schedule is fundamental for the health and productivity of shift workers and usually brings with it an increase in production and better costs. Only healthy and satisfied employees are motivated, committed, capable and willing to perform. There are so many variables in the shift system that a recommendation can hardly be made. The special framework conditions of the company and the employees must be addressed in order to make shift work as gentle as possible. However, many studies have shown the following basic rules for creating “healthy shift schedules”.


Here is a brief overview of the basic rules that should be considered when planning shifts:

a. No more than three consecutive night shifts

The human body does not get used to night shifts. Therefore, the night shift blocks should be as short as possible in order to relieve the organism somewhat. In addition, short changes can prevent the accumulation of sleep deficits.

b. Fast changes and forward rotating shifts

(Early, late, night) - Fast rotation (e.g. the 2-2-2-3 rotation) makes it easier for the body to switch from one working time to the next and is therefore demonstrably gentler in the long term. Where possible, the layer should rotate forward. From early to late shift and from late to night shift. It is best not to start the morning shift between four and five o'clock. At this time, shift workers are usually in the middle of a deep sleep phase. The forward rotation - i.e. the gradual lengthening of the day - corresponds more to our biorhythm.

c. Take time off as a block, not as individual days

Shift work is usually better remunerated. There are night surcharges to reward the employees' commitment. Compensation in the form of increased leisure time for health would be the better solution. Connected days off are particularly valuable for relaxation and quality of life.

d. Sufficient rest between two shifts

(At least eleven hours) Regeneration phases are essential for the health of shift workers

e. Short shifts for heavy work

Shift plans should take into account the type of activity or the difficulty of the work when determining the length of the shift. Physical and mental stress should be taken into account and the working time, especially in the late and night shift, should be shortened if necessary.

f. "Disarm" tasks in the night shift

Many companies organize their work tasks in such a way that the "lighter" tasks are done in the night shift and harder or work that requires a high level of concentration is done in the day shift.


It should be noted that there is no generally applicable, ideal shift schedule. There are a myriad of different variations of shift schedules, each with their own advantages and disadvantages. However, there are good models for operation that are tailored to specific operational requirements.

Healthy organization of shift work - health-oriented and demographically appropriate shift models


Best practice examples for health-friendly shift models at Volkswagen AG & Robert Bosch GmbH

The Volkswagen company, for example, switched to a 17-shift model with four shift teams since the beginning of 2011. There are now a maximum of two early and late shifts and a maximum of 3 night shifts in a row. The around 1,100 VW employees who work in the shift system benefit from the rapid change of shifts and longer periods of rest.

At Robert Bosch GmbH's main plant in Reutlingen, there are two days of early, late and night shifts, one after the other; after that, employees have six days off. The old model (four days of early, late and night shifts alternating) was replaced by the new shift model in 2012 after a test phase. Employees were actively involved in the design of the shift schedule. Surveys took place before and during the changeover; the employees were asked to keep sleep and well-being logs, and after the test phase there was a vote on the question of whether the new system should be introduced. The final assessment from an occupational health point of view showed a significant decrease in health problems associated with night work, a decrease in absenteeism and an increase in the popularity of continuous work among employees.

In principle, it can be said that far-reaching changes in the shift system work best if the employees affected by the changes are involved in the decision-making and implementation process.


4. Take health into your own hands

Not only the company is responsible for containing the risks resulting from night work and shift work. The shiftworkers themselves can, by paying special attention to their health, contain the harmful effects of shiftwork. Above all, factors such as sleep, diet, exercise and social contacts play a role here.

a. Sleep & sleep-promoting measures

The normal sleep rhythm is interrupted by shift work. Shift workers, especially night shift workers who sleep during the day, therefore often suffer from insomnia. Daytime sleep is more prone to disruptions and is often threatened with interruptions. It is therefore shorter, more prone to failure, not as deep and less relaxing. Studies have shown that disturbed daytime sleep leads to more health problems in the long term, including poor concentration, nervousness and premature fatigue, loss of appetite and stomach problems. Cardiovascular diseases and mental disorders can also result from lack of sleep due to shift work.



a) Try to get back to your normal sleep rhythm! You may need to fall back on several sleep phases during the day: a main sleep phase in the morning, which should not be shorter than four hours, and a second sleep phase in the late afternoon. A total of seven hours of sleep per day are important for health, well-being and performance. Short “power naps” in the afternoon are useful.

b) Protect yourself from interference from light and noise! Switch off unnecessary sources of interference (e.g. doorbell, cell phone) and choose the quietest room in the house for the bedroom (away from the kitchen and bathroom). Also, teach neighbors and family members and ask them to keep this calm during their sleep.

c) Ensure that your bedroom is well ventilated! Sleep cool and dark!

d) Do not use sleeping pills or alcoholic beverages as sleep aids,as these reduce the recreational value of sleep!

e) Use natural relaxation techniques instead,e.g. autogenic training, progressive muscle relaxation, etc. back before bed!

f) Do not drink coffee and other beverages containing caffeinein the last 4 hours before going to bed!


b. Diet as a shift worker

Our body aligns itself with its need for food intake and digestive work according to the day-night rhythm. Shift work is accompanied by many changes in personal daily routines, such as changed meal times and eating habits. Since an irregular diet often causes gastrointestinal problems, it is important to follow a normal eating rhythm as closely as possible.



a) Regularity in the diet
Eat at least three, preferably five, small meals a day.

b) Do not feast lavishly before the start of the shift or before going to bed.
Heavy, fatty and carbohydrate-containing food reduces performance because the gastrointestinal tract has to work harder. You should therefore opt for light food before the start of the shift (ideal: lean meat, fish, yoghurt, wholemeal bread, etc.). A light breakfast should also be eaten after returning home from the night shift so that you can sleep better.

c) Sufficient fluid intake
Two to three liters of fluid should be consumed a day. Teas, water and juice spritzers are best for quenching thirst. Cola and lemonades should be avoided.


c. Exercise as the best medicine for shift-related illnesses

Research shows that people who do sports are healthier, happier and more balanced. Above all, exercise in the fresh air, i.e. in changing weather conditions and UV radiation, have a positive effect on the release of stress-reducing and mood-enhancing hormones. The result is a better mood and stamina. In addition, “active employees” experience fewer cardiovascular diseases, depressive moods, obesity and metabolic diseases. However, due to their staggered and irregular working hours, shift workers often have limited opportunities to do sports, e.g. in sports clubs.


a) Exercise and exercise regularly.Many sports such as swimming, cycling or walking do not require partners, teams or clubs.

b) Rely on amateur athletes and privately organized sports programs with friends / family.This gives you more flexibility.

c) You may even find a sports partner on the same shift.This makes it easier to coordinate common sports activities.

d) Integrate more exercise into your everyday life.Come to work on foot or by bike. Instead of taking the elevator, walk up the stairs. Activities such as gardening or short walks are also considered health-promoting exercise.

d. Social contacts for health promotion

Shift workers often complain about limited opportunities to maintain social contacts due to their working hours. It is generally known that a stable social network is the “number 1” health resource. If social networks break down, there is an increased risk in critical life situations, e.g. not being able to cope with psychological stress sufficiently, falling into addictive behavior or developing manifest depression and developing burnout syndrome. The risk of social isolation can best be prevented if leisure activities with friends and family are consciously planned and carried out.



a) Try to have family meals together as often as possible

b) Make up for missing quantity with quality. For example, plan special excursions on a free Saturday

c) Consciously plan and carry out leisure activities with friends

d) Talk to your supervisor in good time about your wishes and needs with regard to the design of the shift schedule




It is very clear that shift work cannot be done without. Also that there are certain risks associated with working around the clock. It is therefore important that each individual shift worker first cares for his or her health and performance, e.g. through regular company medical examinations and a healthy lifestyle. Finding a balance between work and leisure and actively taking care of your physical fitness is of central importance, especially for employees who work against their internal clock. Task of the employee.

The task of the company is to ensure health-promoting framework conditions and to identify those shift systems that are associated with the least negative effects on the health of their employees.

Taken together, this is the prerequisite for the company to maintain its competitiveness and for employees to stay healthy in shift work over the long term.

UBGM guest author: Alena Knabe, Psychologist (BA)


You can find more links on the topic here:

»Information about our seminar“ Healthy in shift work ”»

»Information about our seminar“ Healthy design of shift work ”»

»Seminars, trainings, workshops & courses for adequate stress management»

»Information on the subject of (work) life balance in the relevant practical guide»

»The practical guide to the topic of burnout prevention»


Further sources:

  1. Occupational Medicine Colloquium (2011). German Social Accident Insurance, Heidelberg
  2. Rudolf Karazmann, Effects of shift work, quality of life and personal development, appeared in a conference report of the Austrian network for workplace health promotion on the subject of shift work.


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