INTRODUCTION

Most of the young females are experiencing menstruation related symptoms, and these can lead to problems in their academic and social life (1,2). In consequence of painful menstruation is perceived as usual, and ordinary by exposed individuals it is difficult to determine the exact prevalence. But estimates range from 45% to 95% (3-5).

Menstrual pain is mostly perceived in the lower abdomen but can spread to the lower back, and/or upper legs. Researches, and clinical investigations have shown that pain is caused by uterine prostaglandins, and overproduced vasopressin (6-8). Other symptoms associated with menstruation include diarrhea, nausea, vomiting, poor concentration, back pain, fatigue, and even syncope (1). Premenstrual symptoms such as abdominal pain, headache, nausea, swelling, tenderness, and anxiety are also frequent in young females (7).

Although menstrual disorders are so frequent in young females most of them do not consult to a proficient, related to the belief of it will not help (9,10). Drugs alleviate pain or symptoms by affecting prostaglandin production in menstruation. Intra-uterine devices may also be used in the management (6). Gynecologists agree that the multidisciplinary approach should be preferred for the management of symptoms (3). Non-pharmalogical treatments include herbal products, dietary supplements, nutritional changes, and physical training.

The idea that exercise is effective in preventing, and reducing symptoms has been dominant for many years (1). It is thought that the symptoms may be reduced during exercise as a result of increased metabolism, and blood flow to the uterus. Therapeutic exercise has also been reported to increase endorphin release in the brain, and increase the body’s pain threshold (1,8,9). Several observational and fewer experimental studies have reported that physical activity or exercise is associated with a reduction in menstrual symptoms (4,7,9,11-15). But according to the reviewers, the researches in this field are insufficient particularly in assessment processes and methodology (1,8).

This study was planned extensively in the direction of the deficiencies in the literature and the recommendations of the researchers. Our aim was to investigate the effectiveness of a four-week group aerobic training program on premenstrual symptoms, menstrual symptoms, emotional state, and quality of life in females with primary dysmenorrhea.

METHOD

Study Design and Participants

The current research was performed as a prospective, randomized controlled experimental study. This study was carried out with the students staying in Bülent Ecevit University Dormitories which is located in the Black Sea Region of Turkey and the data were collected between September and December 2017. All the subjects volunteered to participate in this research, and signed the informed consent form approved by the Bülent Ecevit University Clinical Research Ethics Committee (Protocol no: 2017-73-09/08).

Females with self-reported dysmenorrhea in the age group of 18-25 participated in this study. Having regular menstrual cycles (21-35 days), and menstrual pain scoring at least 4 on a 10 cm visual analogue scale (VAS) for previous two consecutive months were inclusion criteria. Pregnancy, known genital and chronic diseases, having intra-uterine contraceptive devices and taking oral contraceptive pills during the study were exclusion criteria. Additionally participants in the control group (CG) who participate any regular physical activity during the study and the participants in aerobic exercise group (AEG) who fail to attend at least 10 of 12 sessions would be excluded from the study.

Fourty-five eligible participants were randomly assigned to either AEG, (n=23), or CG (n=22) using the paired numbers for AEG and non-paired numbers for CG. Five participants of AEG and three participants of CG have been excluded from the analyses owing to drug use and low attendance to the training sessions. The final sample size was 37, as the sum of 18 participants from AEG, and 19 participants from CG (Figure 1).

Outcome Measurements

Demographic features of the participants, including age (year), weight (kg), height (m) and menstrual history including menarcheal age (year), menstrual interval (day), menstrual duration (day) were recorded at the baseline. Dependent variables including premenstrual symptoms, menstrual symptoms, emotional state and quality of life were conducted in two consecutive menstrual phases by the observers who were masked to group assignment.

Premenstrual Symptoms: Premenstrual Symptoms were assessed with the premenstrual syndrome scale (PMSS) which is a 44-item five-point likert-type scale (16). Scale includes nine dimensions of depressive affect, depressive thoughts, nervousness, sleep changes, anxiety, fatigue, pain, appetite changes, and bloating and total score is the sum of the scores of these nine sub-dimensions. The higher score indicates the greater prevalence of premenstrual syndrome symptoms.

Menstrual Symptoms: An evaluation form was designed to assess the intensity of menstrual symptoms (Appendix ). In this form, the intensity of pain, headache, nausea, dizziness, and fatigue parameters were respectively assessed with 10-cm VAS. Upon described of VAS to the participants, seven forms were given to each participant and they were requested to mark the scales at the onset of the bleeding and in the 2^nd, 6^th, 12^th, 24^th, 48^th, and 72^nd hours following the bleeding.

Emotional State: Beck anxiety inventory (BAI) was used to evaluate the anxiety symptoms which is a 21-item self-report questionnaire (17). For the assessment of depressive symptoms, Beck depression inventory (BDI) was used (18). This index is also composed of 21 questions similar to BAI. The higher score indicates a more severe anxiety, and depression according to these scales.

Quality of Life: Short form-36 (SF-36) which is a multidimensional test was used to assess the quality of life of the participants (19). SF-36 is comprised of functional capacity, physical aspects, bodily pain, general health, vitality, social aspect, emotional aspect, and mental health domains and a higher score indicates a better quality of life.

Intervention

Participants in the AEG participated in a four-week group aerobic training program, three times a week during four weeks under the supervision of an experienced physical therapist. The duration of each session was approximately 50 minutes which is comprised five minutes of warming up, 40 minutes of aerobic fitness exercising, and five minutes of cooling down. The trainer demonstrated each exercise using verbal, and visual instructions. All the exercises were performed coordinated in the group.

Statistical Analysis

Statistical analysis was performed with SPSS for Windows release 19.0.0/2010 (IBM-SPSS Inc., Chicago, IL). Level of 5 % was used to determine significant differences. Normality tests (visual, and analytical) revealed that continuous variables were not normally distributed. Demographic data, and baseline outcomes of two groups were compared using Mann-Whitney U test. Intra-group analysis of the dependent variables were conducted using Wilcoxon signed-rank test.

RESULTS

The results of this study showed that there were no significant differences between the AEG, and CG in terms of demographic features including age (years), height (cm), weight (kg), and BMI (kg/m²) (p>0.05). Groups were also homogeneous based on menarcheal age (year), menstrual interval (day), menstrual duration (day), and the scores of the PMSS, BAI, BDI, SF-36 (p>0.05) (Table 1).

PMSS score significantly decreased in the AEG (p=0.012) while such outcomes did not change in CG in the second menstrual phase (p>0.05) (Table 2).

There were no significant differences between initial and final outcomes in the both of the groups in terms of anxiety and depression scores (p>0.05) (Table 2).

Solely, social aspect domain significantly increased in the second menstrual phase in AEG (p=0.044) while none of the domains of quality of life changed in CG between two consecutive menstrual phases (p>0.05) (Table 2).

According to menstrual symptom outcomes, low back pain at the beginning of the bleeding (p=0.012), and abdominal pain at the 2^nd hour decreased (p=0.021) in AEG after intervention (Table 3). Abdominal pain at the beginning of bleeding (p=0.032), and intensity of nausea at the 12^th hour decreased (p=0.026) in CG in the second menstrual phase (Table 4). Remaining of menstrual symptoms did not change in the both of the groups (p>0.05).

DISCUSSION

This study revealed that a four-week group aerobic training program is effective at reducing premenstrual symptoms, slightly decreasing menstrual pain, and contributed quality of life of in terms of social aspect of young females with primary dysmenorrhea. However, this training program did not alter the severity of anxiety and depression. Some of the results of this research are consistent with previous reports while some of them contradict.

Although the averages of menarcheal age, menstrual interval, and menstrual duration concerning the participants were regarded within the normal range for premenopausal women, this could not prevent them from experiencing premenstrual and/or menstrual symptoms.

Premenstrual symptoms are known as the common complaints that begin a few days prior to bleeding (10). The results of the previous studies investigating the relationship between physical activity, and premenstrual symptoms are conflicting (20-27). A cross-sectional descriptive analytical study showed that there was no significant relationship between the frequency of premenstrual syndrome (PMS), and physical activity (21). On the contrary, in another study the occurrence of PMS was observed less in the physically active group than of the sedentary group (22). In the current study premenstrual symptoms of the participants diminished after a four-week group aerobic training program. Our findings related to premenstrual symptoms are similar to the results of some previous researches that are conducted with aerobic exercise programs (23-25). However different exercising methods, and training durations were conducted in such studies as distinct from our study. Mechanisms of contributing to reduce premenstrual symptoms had been associated with endorphins in the previous reports (9,28,29). Aerobic activity may produce perception of wellness, decrease stress, and diminish premenstrual symptoms by the way of releasing brain chemicals such as endorphins. When a large amount of endorphin is secreted from the brain, it brings happiness, and relief to the individual.

Premenstrual symptoms with the onset of bleeding leave its place to menstrual symptoms. Pain is the most common menstrual symptom, and is perceived especially in the pelvic region, low back, and thighs. During painful menstruation, uterine contraction is constricted by an excessive increase in prostaglandin, which causes vasospasm of uterine arterioles. It may cause ischemia, and cramps in the abdominal area which evoke menstrual pain (30). Several studies have been carried out to investigate the effectiveness of different exercise methods in menstrual pain, and it has been reported that exercise can reduce pain by increasing lung capacity, metabolism, blood flow to uterine, and endorphin hormone release (30). Indeed, although it seems plausible to encourage exercise as a treatment for menstrual pain, researches in this field have not been able to demonstrate sufficient evidence (31). Methodological quality of these studies is weak, and the data obtained from them are not considered as evidence. One lack is that there is no explanation in such trials about the current time of pain assessment or anatomical localization of the pain. It is known that menstrual pain may begin at the beginning of the bleeding, and lasts for three days with increasing or decreasing intensity. Thus, it is not a realistic approach to assess the pain objectively by a single evaluation for the whole menstrual period. Furthermore, it has not been reported in previous studies that this single assessment was conducted either immediate the participants perceived the pain or long after. We planned our study considering this limitation in the literature, and evaluated pain at seven different times for three different anatomical region during the menstrual period. After four weeks of aerobic exercise training low back pain at the beginning of bleeding, and abdominal pain at the 2^nd hour decreased in AEG while abdominal pain at the beginning of bleeding, and intensity of nausea at the 12^th hour decreased in CG. It is possible to interpret this result as exercising provides positive effects on pain solely at the initial of the menstruation phase. But also the presence of diminished symptoms in the CG makes it difficult to interpret the results objectively. At this point, our opinion is that other factors that we cannot control such as seasonal changes or personal reasons might affect the result. It is not possible to mention on consistency of our results with the previous studies yet the authors did not report sufficient information about the localization or the current time of pain assessment in those reports (9,28,29).

The intensity of premenstrual, and menstrual symptoms may also lead to stress, and mood disturbances in women (30). Yet there is not enough evidence that aerobic exercise is effective in decreasing depression, and anxiety in healthy populations, or patients with psychiatric disorders, some of the previous studies showed that exercise improves general mood, reduces depression, and anxiety levels in women with dysmenorrhea (24,31). However our study exhibited nonsignificant trends of improvement in anxiety, and depression in the participants.

Painful menstrual cramps cause reduction in quality of life during menstruation and future studies should investigate whether quality of life is restored with effective treatment (32,33). The positive effects of exercise training in quality of life in women with dysmenorrhea, and PMS were previously reported (6). In the consistency with literature, social aspect domain of SF-36 significantly increased after intervention in the current study. Although it could not be possible to completely improve the quality of life of our participants in a relatively short time, the outcomes of intervention group showed a rising trend. We think that performing exercises in the form of group training might be effective in order to ensure a faster improvement in the social aspect domain of quality of life. According to our findings, aerobic exercising can be encouraged to achieve a better quality of life in women during menstruation cycle.

There are several studies investigating the possible benefits of physical activity on menstrual complaints, but such studies vary in terms of human population, exercise protocol, training duration, intensity of exercise, and outcome measurements. The reason of that the results of the current study are in contrast with some of the previous studies may be due to that our assessment method is obviously more detailed, and objective compared to such studies.

Study Limitations

The marked limitation of our study was sample size. Dropped out number was more than expected due to drug using in consequence of unbearable menstrual pain, and low attendance to the training sessions.

CONCLUSSION

In conclusion, a four week group aerobic training program was effective in reducing premenstrual symptoms, contributed to the pain reduction, and improved quality of life in women with primary dysmenorrhea. However, this training program could not alter depression, anxiety, or menstrual symptoms except pain. We think that the current study is valuable in terms of providing a new approach related to using of more detailed, and objective assessment methods.

Ethic

Ethics Committee Approval: Ethics committee approval was received for this study from the ethics committee of Bülent Ecevit University (Protocol no: 2017-73-09/08).

Informed consent: Informed consent was obtained from all individual participants included in the study.

Peer-review: Externally peer-reviewed.

Author Contributions

Concept: E.U.E., Design: E.A., Data Collection or Processing: E.U.E., Analysis or Interpretation: E.U.E., Literature Search: E.U.E., E.A., Writing: E.U.E

Conflict of Interest: The authors declare that they have no conflicts of interest.

Financial Disclosure: The authors declared that this study has received no financial support.