The exercise program consisting of deep breathing and progressive muscle relaxation exercises was applied to the students in the exercise group. The first exercise session was started the day after the training about the study. During the study period, the program was started at the end of school hours of high school students for a total of 20 sessions (4 weeks, every weekday), each session lasting 30 minutes. The sessions started with deep breathing exercises, continued with progressive muscle relaxation exercises, and ended with deep breathing exercises.

For deep breathing exercises, students were asked to place their dominant hand on their abdomen and non-dominant hand on their chest in the semi-fowler position. Afterwards, they were instructed to breath deeply through their nose for 4 seconds and exhale through their mouth for 8 seconds. These exercises were performed as 4 repetitions with 2 minutes rest time between the exercises. When the deep breathing exercise

no treatment was applied to student in the control group.

For deep breathing exercises, students were asked to place their dominant hand on their abdomen and non-dominant hand on their chest in the semi-fowler position. Afterwards, they were instructed to breath deeply through their nose for 4 seconds and exhale through their mouth for 8 seconds. These exercises were performed as 4 repetitions with 2 minutes rest time between the exercises. When the deep breathing exercises were finished, the students lay on their backs and rested for 1 minute and then progressive muscle relaxation exercise was started (10,11).

For the progressive muscle relaxation exercise, the students were asked to contract and then relax the right foot, left foot, right leg, left leg, hip, abdominal muscles, chest muscles and back muscles, right hand, left hand, right arm, left arm, neck and shoulders, and facial muscles respectively. Respectively, from bottom to top, all the major muscles are contracted while inhaling deeply and slowly, and relaxed and r

Cornell Musculoskeletal Disorder Questionnaire (CMDQ): The scale was adapted into Turkish by Erdinç et al. in 2008. This scale assesses the frequency and severity of pain, soreness or discomfort in 11 different body parts (neck, shoulder, back, upper arm, waist, forearm, wrist, hip, upper leg, knee and lower leg) in the last 7 days and whether it interferes with work. Weight scores are calculated according to the answers given for frequency, severity and inability to work.The frequency of pain, aching or discomfort was graded from never (0) to many times every day (4); the severity was graded from mildly severe (1) to very severe (3); and the effect on work performance was graded from never interfered (1) to very much interfered (3). The weighted score for each body part takes a value between 0 and 90.

Well-being Star Scale (WSS): It is a questionnaire developed by Korkut and Owen in 2016 at the university. The first dimension 'making sense of life and being goal-oriented' consists of seven items (1, 6, 11, 16, 21, 23, 24). The second dimension 'cognitive dimension' consists of four items (2, 7, 12, 17). The third dimension, 'emotional dimension', consists of five items (3, 8, 13, 18, 22). The fourth (4, 9, 14, 19) and fifth (5, 10, 15, 20) dimensions consist of four items each and are named as 'physical dimension' and 'social dimension' respectively. The items are scored using a five-point Likert scale. The scores that can be obtained from the scale vary between 24-120 and the higher the score, the more positive the individual's well-being is interpreted.