Participants will be instructed and trained with two stress management techniques (Diaphragmatic Breathing- DB and Progressive Muscle Relaxation-PMR), along with biofeedback training in diaphragmatic breathing.

During the eight weeks of the program, participants in the intervention group will receive information regarding stress, work-related stress factors, musculoskeletal health and disorders, the Medically Unexplained Symptoms-MUS, occupational psychosocial hazards, lifestyle habits (healthy diet, sedentary life, sleep, hygiene).

Moreover, participants will be informed about how to manage stress related factors at the workplace, and its symptoms, through lifestyle modifications along with ergonomic guidance at work and in relation with their musculoskeletal health, the psychosocial hazards at work and their body response to work-related stress.

Participants will receive only information regarding ergonomic practices and tips able to be appilied at the workplace.

Diaphragmatic breathing (DF), also known as belly or abdominal breathing, is a technique that can teach people how to use their diaphragm correctly while breathing, in order to activate the parasympathetic branch of the autonomic nervous system and to control stress.

Heart Rate Variability (HRV) has been widely used as an indicator for work-related stress. It measures the variation in time between each heartbeat and is controlled by the autonomic nervous system.

Salivary cortisol has been used as an indicator for stress. Pre-post intervention differences between diurnal circadian rhythm in the saliva cortisol of the participants will be measured, in order to evaluate the efficiency of the intervention upon homeostatic load.

Musculoskeletal symptoms will be assessed with the Nordic Musculoskeletal Questionnaire (NMQ). NMQ is a standardized questionnaire for the assessment of musculoskeletal problems in nine different body regions (neck, shoulders, upper back, elbows, wrist/hands, lower back, hips/thighs, knees, ankles/feet). General questions include 40 forced-choice items where responders could indicate if they had musculoskeletal problems (aches, pain, discomfort) in the last 12 months or seven days. Additional questions ask the participants to report if the musculoskeletal problems had led to inability to perform daily tasks and normal activities.

Work-related stress can lead to physical strain, which in turn can lead to musculoskeletal tension and disorders. Musculoskeletal disorders (MSDs) are a common type of occupational diseases and have become the main cause of absenteeism and early retirement in the working population.

Quality of life will be measured with the Short Form survey (SF-36) self-report questionnaire. SF-36 provides comprehensive information of an individual health status and assesses eight domains of health such as: Physical functioning, Role limitations due to physical health, Role limitations due to emotional problems, Energy/ fatigue (vitality), Emotional wellbeing, Social functioning, Pain, and General health. It provides valuable insights into participants' perceived health status and overall quality of life. All questions are scored on a scale from 0 to 100, reflecting a range from lowest to highest possible quality of life.

Scoring the SF-36 involves a two-step process. At first each question must be pre- coded with a numeric value which is then recorded according to a scoring key and then the second step involves averaging the recorded values from items within the same scale to compute the total scale score.

Psychosocial work-related stress factors will be measured with the Copenhagen Psychosocial Questionnaire (COPSOQ-II medium version). The medium version of the questionnaire consists of 8 domains, 28 dimensions and 87 items. Each item scores from 0-100 (i.e. 0, 25, 50, 75, and 100 for a five response category item). The scale score is computed as the mean item score. Higher total score indicates that the employee experiences greater work-related psychosocial risk factors.