In this study, we found a relationship between regular PA and PMS symptoms. This study clarified two results. First, people with a PA of 3000 METs/week or more had lower scores for psychological and physical symptoms. Second, the ratio of participants who had more than 3000 METs/week had no symptoms.
PMS is one of the most common problems among women. Moreover, PMS can interfere with activities of daily living. Thus, finding a way to prevent or treat PMS is an important health and research priority. In our study, we found that over 90% of women reported at least one symptom of PMS. This findings was similar to a study that found that 95% of participating women aged 18-24 years experienced at least one PMS symptom.
Our first conclusion was that people whose PA is more than 3000 METs/week had lower scores in psychological and physical symptoms. This conclusion complemented Koushkies et al.’s finding, which showed an association between an increased PA and a significant reduction in PMS symptoms . However, Kroll-Desrosiers et al.’s study showed no evidence of an association between PA and either the presence of PMS or premenstrual symptom severity . The difference must have been due to the difference in method. Kroll-Desrosiers et al.’s examined PA by continuous METs per week and analysed the data by dividing the group by tertiles of PA. Higher levels of participation were characterised using the IPAQ, which defined vigorous-intensity activity 3000 MET-minutes/week or more. Furthermore, we used 3000 MET-minutes/week because this number approximated the recommended levels (150 minutes of moderate-intensity physical activity per week) of PA after calculation .
Regarding the second conclusion, the ratio of participants who had more than 3000 METs/week had no symptoms. The symptoms we found in this study were ‘sleepiness’, ‘acne’, ‘feeling depressed’, ‘decreasing concentration’, and ‘easily fatigued and feeling listless’. Some studies explained this phenomenon. Wilmore et al. showed that regular PA had many benefits, including reduction of stress and PMS . Additionally, PA might still affect sex hormone function by modulating target tissue sensitivity to these hormones . A previous study showed a significant decrease in prolactin, oestradiol, and progesterone levels, resulting in fatigue, impaired concentration, confusion, and most PMS symptoms. In addition, a study showed that increased prolactin level in the late luteal phase was one of the causes of breast pain and swelling. PA in non-athletes possibly reduces the status of this hormone; thus, the ratio of breast pain and swelling may be reduced. However, our results did not corroborate with this finding . PA, including resistive exercise, induces neuroimmunomodulation effects, increases neurotrophies and β-endorphins, decreases the sympathetic response, affects the hypothalamic-pituitary-adrenal axis reactions, and improves the serotonin system. All of these responses may decrease anxiety and depression .
Acne is a symptom associated with polycystic ovarian syndrome and is a common metabolic disturbance, particularly in women . A study suggested that regular exercise decreased plasma insulin levels and reduced metabolic disease . Sleep and activity during awake time interact to influence many aspects of health . Moreover, a study showed that age and sex were associated with PA and sleep. They found that aspects of PA were significantly lower in younger adults (20-39 years old) who reported more frequent daytime sleepiness .
Priya et al. studied the effect of aerobic exercise at different intensities on PMS and concluded that moderate-intensity aerobic exercise should be encouraged as a potential prophylaxis for PMS . This study gave us a range of PAs that they investigated. In this study, we converted different intensities of exercise into numbers that were calculated from the participants’ daily PA. We were not simply considering exercise alone, but also the overall PA. In addition to high-intensity exercise in participants engaged in sports, we also examined the presence of daily moderate-intensity exercise and walking time.
In addition, we considered that PMS symptoms affected daily PA. A systematic review and meta-analysis indicated that exercise performance might be trivially reduced during the early follicular phase of the menstrual cycle compared with all other stages . We considered the possibility that PMS symptoms affected exercise. Although some of the participants’ PA included high-intensity exercise in our study, it could not be denied that PMS affected PA.
Thus, according to our results, women with 3000 METS/week or more of PA had milder symptoms of PMS.
Researchers frequently rely on questionnaires to assess PA because of their low cost and ease of administration. However, inherent limitations, such as participant recall bias and an inability to accurately retrospectively recall relevant PA details, may lead to overestimation or underestimation of PA. The target is limited, and causality is not known. The IPAQ-short version typically overestimates PA as measured by an objective criterion by an average of 84% .