• The Turkish Version of the Chalder Fatigue Scale [ Time Frame: About 2-3 minutes ]
  The Chalder Fatigue Scale has a 7-item physical fatigue subscale and 4 items of mental fatigue subscale. The scale evaluates the severity of physical and mental fatigue over the last month. Each item is scored 0-3 (0=less than usual, 3=much more than usual), yielding a total between 0 and 33.
• The Turkish Version of the Checklist Individual Strength Fatigue Scale [ Time Frame: About 3-4 minutes ]
  The scale evaluates fatigue over the past two weeks.The questionnaire consists of 20 items with a 7-point Likert scale scoring. A total score is derived by summation of the item scores (20-140). There are four subscales; Fatigue Severity, measuring the subjective experience of fatigue (8 items); Concentration, measuring concentration problems (5 items); Motivation, measuring reduced motivation (4 items) and Activity, measuring the reduction of activities (3 items).

• The Turkish Version of the Chalder Fatigue Scale [ Time Frame: 30 days ]
  The Chalder Fatigue Scale has a 7-item physical fatigue subscale and 4 items of mental fatigue subscale. The scale evaluates the severity of physical and mental fatigue over the last month. Each item is scored 0-3 (0=less than usual, 3=much more than usual), yielding a total between 0 and 33.
• The Turkish Version of the Checklist Individual Strength Fatigue Scale [ Time Frame: 14 days ]
  The scale evaluates fatigue over the past two weeks.The questionnaire consists of 20 items with a 7-point Likert scale scoring. A total score is derived by summation of the item scores (20-140). There are four subscales; Fatigue Severity, measuring the subjective experience of fatigue (8 items); Concentration, measuring concentration problems (5 items); Motivation, measuring reduced motivation (4 items) and Activity, measuring the reduction of activities (3 items).
• Visual Analog Scale to Evaluate Physical and Mental Fatigue [ Time Frame: 30 days ]
  Self reported physical and mental fatigue severity over the last month. It is scored 0=no fatigue; 10= tired as bad as can be

• Visual Analog Scale to Evaluate Physical and Mental Fatigue [ Time Frame: About 1 minutes ]
  Self reported physical and mental fatigue severity over the last month. It is scored 0=no fatigue; 10= tired as bad as can be
• The Turkish Version of the Pittsburgh Sleep Quality Index [ Time Frame: About 2-3 minutes ]
  The scale assesses sleep quality over a 1-month period. The questionnaire consists of 19 self-rated questions and 5 questions that should be answered by roommates. The latter questions are used only for clinical information. The 19 questions are categorized into 7 components, graded on a score that ranges from 0 to 3. The scale's components are as follows: subjective sleep quality (C1), sleep latency (C2), sleep duration (C3), habitual sleep efficiency (C4), sleep disturbances (C5), use of sleeping medication (C6) and daytime dysfunction (C7). The sum of scores for these 7 components yields one global score, which ranges from 0 to 21, where the highest score indicates worst sleep quality.
• The Turkish Version of the Beck Depression Inventory [ Time Frame: About 4-5 minutes ]
  It is a 21-item self-report questionnaire for assessing the severity of depressive symptoms over past week; the items comprise four ordinal categories (from 0 through 3). Absence (or "as usual") of depressive symptom in each item is scored as "0" and presence of symptom is scored between 1 and 3, with the higher score indicating more intense symptom severity. The possible total score ranges from 0 to 63.
• The Turkish Version of the Nottingham Health Profile [ Time Frame: About 4-5 minutes ]
  The scale measures subjective health status using 38 items that assess 6 subscales (physical mobility, pain, energy level, sleep, emotional reaction and social isolation); each question answered by (yes) or (no) with each question assigned a weighted value. Scores for each section can range from 0 "no problems" to 100 "all problems listed are present" where the sum of all weighted values in a given subscale adds up to 100.

• The Turkish Version of the Pittsburgh Sleep Quality Index [ Time Frame: 30 days ]
  The scale assesses sleep quality over a 1-month period. The questionnaire consists of 19 self-rated questions and 5 questions that should be answered by bedmates or roommates. The latter questions are used only for clinical information. The 19 questions are categorized into 7 components, graded on a score that ranges from 0 to 3. The scale's components are as follows: subjective sleep quality (C1), sleep latency (C2), sleep duration (C3), habitual sleep efficiency (C4), sleep disturbances (C5), use of sleeping medication (C6) and daytime dysfunction (C7). The sum of scores for these 7 components yields one global score, which ranges from 0 to 21, where the highest score indicates worst sleep quality.
• The Turkish Version of the Beck Depression Inventory [ Time Frame: 7 days ]
  It is a 21-item self-report questionnaire for assessing the severity of depressive symptoms over past week; the items comprise four ordinal categories (from 0 through 3). Absence (or "as usual") of depressive symptom in each item is scored as "0" and presence of symptom is scored between 1 and 3, with the higher score indicating more intense symptom severity. The possible total score ranges from 0 to 63.
• The Turkish Version of the Godin-Shephard Leisure Time Physical Activity Questionnaire [ Time Frame: 7 days ]
  It was developed to classify physical activities/exercises performed by adults and to determine their activity levels. Activities were classified into three subgroups, including "strenuous", "moderate" and "light"The frequency and type of activities/exercises performed weekly by individuals were used as criteria while calculating individuals' physical activity/exercise score in the questionnaire: total score = strenuous/exhausting (9 METs × times/week) + moderate (5 METs × times/week) + light (3 METs × times/week).
• The Turkish Version of the Nottingham Health Profile [ Time Frame: 30 days ]
  The scale measures subjective health status using 38 items that assess 6 subscales (physical mobility, pain, energy level, sleep, emotional reaction and social isolation); each question answered by (yes) or (no) with each question assigned a weighted value. Scores for each section can range from 0 "no problems" to 100 "all problems listed are present" where the sum of all weighted values in a given subscale adds up to 100.

• Fatigue
• Healthy

• Mota DD, Pimenta CA. Self-report instruments for fatigue assessment: a systematic review. Res Theory Nurs Pract. 2006 Spring;20(1):49-78. Review.
• Beydoun J, Nasrallah L, Sabrah T, Caboral-Stevens M. Towards a Definition of Caregiver Fatigue: A Concept Analysis. ANS Adv Nurs Sci. 2019 Oct/Dec;42(4):297-306. doi: 10.1097/ANS.0000000000000262.
• Glaus A, Crow R, Hammond S. A qualitative study to explore the concept of fatigue/tiredness in cancer patients and in healthy individuals. Eur J Cancer Care (Engl). 1996 Jun;5(2 Suppl):8-23.
• Engberg I, Segerstedt J, Waller G, Wennberg P, Eliasson M. Fatigue in the general population- associations to age, sex, socioeconomic status, physical activity, sitting time and self-rated health: the northern Sweden MONICA study 2014. BMC Public Health. 2017 Aug 14;17(1):654. doi: 10.1186/s12889-017-4623-y.
• Cella M, Chalder T. Measuring fatigue in clinical and community settings. J Psychosom Res. 2010 Jul;69(1):17-22. doi: 10.1016/j.jpsychores.2009.10.007. Epub 2009 Dec 11.
• Zwarts MJ, Bleijenberg G, van Engelen BG. Clinical neurophysiology of fatigue. Clin Neurophysiol. 2008 Jan;119(1):2-10. Epub 2007 Nov 26. Review.
• Chalder T, Berelowitz G, Pawlikowska T, Watts L, Wessely S, Wright D, Wallace EP. Development of a fatigue scale. J Psychosom Res. 1993;37(2):147-53.
• Beaton DE, Bombardier C, Guillemin F, Ferraz MB. Guidelines for the process of cross-cultural adaptation of self-report measures. Spine (Phila Pa 1976). 2000 Dec 15;25(24):3186-91. Review.
• Dittner AJ, Wessely SC, Brown RG. The assessment of fatigue: a practical guide for clinicians and researchers. J Psychosom Res. 2004 Feb;56(2):157-70. Review.
• Ergin G, Yildirim Y. A validity and reliability study of the Turkish Checklist Individual Strength (CIS) questionnaire in musculoskeletal physical therapy patients. Physiother Theory Pract. 2012 Nov;28(8):624-32. doi: 10.3109/09593985.2011.654321. Epub 2012 Feb 10.
• Kücükdeveci AA, McKenna SP, Kutlay S, Gürsel Y, Whalley D, Arasil T. The development and psychometric assessment of the Turkish version of the Nottingham Health Profile. Int J Rehabil Res. 2000 Mar;23(1):31-8.
• Wood C, Magnello ME, Jewell T. Measuring vitality. J R Soc Med. 1990 Aug;83(8):486-9.

The inclusion criteria for participants are: to be aged between 20 and 40 years old, volunteer to participate the study, able to read and speak Turkish.

Exclusion criteria are determined as individuals with known acute or chronic health conditions and illnesses and who had surgery in the past 6 months.

Further exclusion criteria are to take over-the-counter medication or food supplement, have abnormal body mass index (BMI) (lower 17 kg/m2 or higher 30 kg/m2), self reported depression as indicated by a score of > 21 on the Beck Depression Scale (BDS), pain as indicated by a score of > 0 on pain subscale of Nottingham Health Profile (NHP). Additionally, female participants were excluded if they use oral contraceptives, experience premenstrual syndrome or were pregnant within the last one year period.