The Relationship Between Menstruation Cycle and Exercise Participation in Korean Female College Students

Background: The purpose of this study was to examine how Korea female university students participate in physiological and psychological exercises according to differences in their menstrual cycles and health consciousness, exercise participation, and exercise intention. This study analyzed how these female students feel about their own health, participating in exercises, and the duration of the exercise according to the different menstrual cycles and their various patterns. Methods: The study surveyed women university students in Gangwon-do, Busan, and Ulsan metro city in Korea. A total of 464 questionnaires were analyzed using the statistical programs SPSS Win 22 and AMOS Win 22. We used cross-analysis, T-tests, one-way ANOVA analysis, and correlation analysis to analyze differences in health consciousness, intensity of exercise, and degree of intent to exercise in terms of the menstrual cycle and exercise pattern during the cycle. Results: First, there were no signicant differences between menstrual pattern (regular vs. irregular) and general exercise periods during the non-menstrual period (X2 = 5.828, p < 0.212). However, the study showed that more female university students who had regular menstrual cycle were back to regular exercise right after their menstruation cycle ended, and the girls with irregular menstrual cycles did not exercise as much right after their menstruation cycle ended. Second, there were signicant differences in the relationship between health consciousness (p = 0.000), amount of exercise (p = 0.002), and grade of intention to exercise (p = 0.002) according to the differences in menstrual cycles and pattern of Korean female university students. Female university students with a regular menstrual cycle showed higher health consciousness, amount of exercise, and intent to exercise than did ones with irregular menstrual cycles. Third, there was a signicant difference in the relationship between health consciousness (p = 0.000), amount of exercise (p = 0.000), and intent to exercise (p = 0.000) in accordance with exercise period (did not exercise, before menstruation, after menstruation, and when not menstruating, always) of Korean female university students. In other words, female university students

generally goes through a period of becoming an adult from adolescence and is prone to health issues because of unhealthy habits and behaviors [2]. Korean university students are exposed to psychological and social stresses that threaten their health (smoking, drinking, irregular eating habits, lack of sleep, etc.) as well as to a competitive social atmosphere, such as staying on top of the class, relationship issues, and worries about employment and career. In particular, they develop irregular lifestyles because of sudden changes in their lives, being given freedom and independence they did not experience before, resulting in an irregular pattern in daily life which leads to some health issues [3]. In other words, most Korean university students are freed from the pressure they had during their high-school days. They are free from social expectations that burdened them while they were in high school, and this sudden freedom often leads them to form irregular lifestyles while not recognizing the importance of their physical and mental health [4]. Another problem is that Korean university students go through excessive diet routines to maintain their body shape in order to seek employment after their graduation.
Unfortunately, this is expected by the society, and these students go through excessive diet routines even though they know it is not good for their health [5,6]. Also, Korean female university students pay great attention to their body shape, diet habits, and exercise. In the end, their self-awareness of their health leads to their behavior.
One obstacle these students face while trying to maintain their health is menstruation. Women's menstrual cycles differ from person to person, but occur, on average, every 28 days [7]. Menstrual phase, proliferative phase, secretory phase, follicular phase, ovulation, luteal phase, and the menstrual cycle is controlled by one's hormones [8]. Menstruation can present complexity in achieving the healthy body and mind these female students wish to have. In particular, female university students are stressful and sensitive due to various factors (study, career, employment, physical health, etc.) [9,10]. Furthermore, women's physiology may cause problems, such as poor academic e ciency, cheating at school, and crime, it may adversely affect an individual or society to the extent that it impairs daily life. From the physical and psychological perspective of female college students, understanding and paying attention to their menstrual attitudes, interests, and con icts is important, and will need to take care of self body. Therefore, the purpose of this study is to analyze the differences in health consciousness, amount of exercise, and intent to exercise according to the menstrual cycle(regular and irregular) and exercise period (before menstruation, after menstruation, and when not menstruating, always) of Korean female university students.

Sampling Method
This study surveyed 500 female university students who are attending K University in Gangwon-do, D University in Busan, and U University in Ulsan. The purpose and content of the study were fully explained to these participants, and a survey was obtained with their consent. A total of 36 surveys were excluded that were not answered properly or were not available for this study out of total 464 surveys answered. This study was approved by the Institutional Review Board of Kangwon National University (2019-04-001-001). It was conducted in accordance with the Declaration of Helsinki. The general characteristics of the study subjects are shown in Table 1. In this study, "regular menstruation" refers to the case of regular bleeding for about 3-7 days at 28-34 days interval every month, and "irregular menstruation" refers to all cases except for this. Also, in the period of exercise, "before menstruation" refers to one week before the rst day of menstruation, and "after menstruation" refers to one week after the last day of menstruation. "Always" refers to every day regardless of menstruation, and "when not menstruating" refers to all days except for the period of menstruation(bleeding).

Health consciousness of the Questionnaire
This study used tools for analyzing the survey questions and differences of individual characteristics of the research subjects. As a survey tool for health consciousness [11,12], the questionnaires used in the previous study (Cronbach's a .890) were directly modi ed by a professor and a researcher to suit the actual condition of this study. The questions on health consciousness were 6 in total: Intention to exercise of the Questionnaire The survey tools [13] on intent to persist in exercise was modi ed from the items used in the previous study (Cronbach's a .915) to suit the present conditions. Questions on intention to exercise were 4 in total: 'I will continue to participate in exercise even if I do not have time', 'I will continue to participate in the exercise', 'I will continue to participate in exercise even though I am tired', 'I will continue to participate in exercise even if I can't afford it'.

Statistical Analysis
The collected data were analyzed using SPSS 22.0 and AMOS 22 in order to con rm whether the collected questionnaires were suitable for factor analysis. Kaiser-Meyer-Olkin (KMO) > .5 and Bartlett test p < .05 were also used. We did an exploratory factor analysis to extract common factors for each question. The factor rotation method used Varimax, a right-angle rotation method. Factor extraction was set to an eigenvalue of 1.0 or more and a factor-loading value of .4 or more. We did con rmatory factor analysis for health consciousness and intent to exercise for exploratory factor analysis.
In order to analyze the validity and reliability of the variables, we measured the tness by a content validity test, Reliability was analyzed using Cronbach's α, and discriminant validity was assessed by AVE.
We used Pearson Χ 2 test, T-test, and one-way ANOVA to analyze the differences in health consciousness, amount of exercise, and intent to exercise according to the menstrual cycle and the exercise period of Korean university college students. Last, to nd out the relationship among factors we carried out correlation analysis.

Exploratory factor analysis
Exploratory factor analysis found that KMO was .934, which was higher than the standard value of .80. The Bartlett test result also showed p = .000, and the sample was appropriate, lower than the baseline of p = .05. The Cronbach's α was more than .9 in the reliability of each factor. AVE was also higher than .8, which ensured reliability and validity. The exploratory factor analysis results are shown in Table 2.

Results
The results of the Pearson Χ 2 test of exercise period according to the menstrual cycle of Korean female university students are shown in Table 4. There were no signi cant differences in the exercise period (Χ 2 = 5.828, p < .212) according to the menstrual cycle. However, the study shows that female university students with a regular menstrual cycle exercise a lot more than do female university students with irregular menstrual cycles after their menstrual cycle end.
The results of the Pearson Χ 2 test shows the difference between health consciousness, amount of exercise, and intention to exercise according to the menstrual cycle of Korean female university students are shown in Table 5. First, there were statistically signi cant differences in health consciousness (p = .000). Female university students with regular menstrual cycles (M = 3.732) had higher health consciousness than did irregular female students (M = 3.416). Second, there were statistically signi cant differences in the amount of exercise (p = .002). Female university students with regular menstrual cycle (M = 2.828) exercised more than did irregular female students (M = 2.401). Third, there were statistically signi cant differences in intention to exercise (p = .002), regular female university students (M = 3.243) intended to exercise more than irregular female university students did (M = 2.992).
The analyzed results of differences between health consciousness, amount of exercise, and intention to exercise according to exercise period of Korean female university students are shown in Table 6. First, the health consciousness index for the female university students who exercised regularly during the nonmenstrual period was higher than that of exercising irregularly. Indexes are as followed; female students who exercise before menstruation ( Finally, to analyze the relationship among variables we brought correlation analysis to effect. As a result, like showing in Table 7, it showed that the relationship among health consciousness, exercise degree and exercise intention had a positive correlation at the p < .05 level.

Discussion
The purpose of this study is to examine how Korea female university students participate in physiological and psychological exercises according to differences in their menstrual cycles and health consciousness, exercise participation, and exercise intention. This study analyzed the relationships between health consciousness, amount of exercise, and intention to exercise according to menstrual cycle and exercise period in Korean female university students. Discussions of the results are as follows.
First, there were no signi cant differences in exercise period according to menstrual cycle in the relationship between menstrual cycle and exercise period of Korean female university students. However, the study showed that female university students with regular menstrual cycles exercise a lot after menstruation compared to female university students with irregular menstrual cycle. In other words, it can be inferred that female university students with irregular menstrual cycle have less tendency to exercise.
The more irregular the menstrual cycle, the higher the menstrual discomfort in women. To relieve menstrual discomfort, an active lifestyle (exercises) is more bene cial in the long run than is a not-soactive lifestyle (such as resting or sleeping excessively, starving, or using painkillers) [14]. In particular, A study of Korean female university students showed only 51.7 ~ 63.0% of female university students had regular menstrual cycles, and more than 30% had irregular menstrual [15,16,17,18]. As shown from the results of this study, it can be inferred that 30% of female university students with irregular menstrual cycle do not exercise as much as they should. Menstrual discomfort occurs in female university students whether they have a regular or an irregular menstrual cycle. However, female university students who participate in exercise will bene t from maintaining a regular menstrual cycle and will be more effective at reducing menstrual discomfort. Therefore, an appropriate exercise program is needed to improve the quality of life for female university students.
Second, there were signi cant differences in the relationships between health consciousness, amount of exercise, and intention to exercise according to the menstrual cycle of Korean female university students. The ones with regular menstrual cycles showed higher health consciousness, amount of exercise, and intention to exercise than did ones with irregular menstrual cycles. A study of women's health showed that the higher the level of concern for health they have, the more they [19]. The rst result showed that female university students who had regular menstrual cycle exercise more often and are more health conscious. Furthermore, it can be inferred that female university students with regular menstrual cycles are more advantageous in terms of amount of exercise and intention to exercise.
Third, there were signi cant differences in the relationships between health consciousness, amount of exercise, and intention to exercise according to the exercise period of Korean female university students. The health consciousness was higher in the ones who exercised before menstruation, after menstruation, and during the non-menstrual period than in those who did not exercise regularly. The amount of exercise was higher in female university students who exercised before menstruation, after menstruation, always, and during non-menstrual period than in those who did not exercise. The intention to exercise was higher in ones who exercised before menstruation, after menstruation, always, and during non-menstrual period than in those who did not exercise. Korean female university students usually have complex physical, emotional, and behavioral symptoms 2 ~ 10 days before menstruation begins and experience a menstrual syndrome that disappears immediately after menstruation (Lim & Park, 2010). In Korea, 80% of women of child bear age complain of premenstrual syndrome, 20% of which are severe and cause di culty in daily life [20] About 82.4 ~ 100% of female university students in their 20 s experience menstrual discomfort [21]. That means over 75% of women experience menstrual syndrome. Menstruation syndrome experienced by women in their teens and late 20 s brings physical and mental symptoms, mood swings, anxiety, loss of control, and fatigue [22,23]. Menstrual syndrome is even referred to as a mental and physical illness that arises from psychological and social interactions [24]. The results of this study show that female university students do more exercise after menstruation, which is psychologically and physically more comfortable than before menstruation. After all, students who exercise a lot are interested in their own health. Furthermore, it can be inferred that the amount of exercise and the intent to exercise are related. Women who participate in exercise during menstruation have fewer menstrual pains than women who do not exercise [25,26]. Therefore, it is positive for Korean female university students to always participate in exercise for long-term health bene t.

Conclusion
In this study, Korean female university students who had regular menstrual cycles exercised regularly and showed a high level of their own health consciousness, amount of exercise, and intention to exercise. Also, female university students who exercise regularly have a higher level of health consciousness, amount of exercise, and intention to exercise. This study will be valuable as a pilot study related to physiological, psychological factors, and exercise of women.
Abbreviations SPSS Statistical package for the Social Sciences; KMO:Kaiser-Meyer-Olkin.

Declarations
Ethics approval and consent to participate This study was approved by the Institutional Review Board of Kangwon National University (2019-04-001-001). It was conducted in accordance with the Declaration of Helsinki. The purpose and content of the study were fully explained to these participants, and a survey was obtained with their consent. All data were collected concerning the participants' privacy and anonymity.

Consent for publication
Not applicable.

Availability of data and materials
The datasets for current study are available from the corresponding author on reasonable request.

Competing Interests
All authors declare that they have no known competing nancial interests or personal relationships that could have appeared to in uence the work reported in this paper.

Authors' contributions
ShK and WSCh contribute to conception of design of the study. iBP implemented the measurements and research data. All authors approved and read the nal version of the manuscript.