Thursday December 17 2009
“Exercise does not help to alleviate period pain, despite it being commonly recommended for women with monthly symptoms,” the BBC reported.
The news report is based on research that asked women aged between 18 and 25 about their period pain and how much exercise they typically did. It aimed to investigate whether there is truth in the anecdotal evidence that exercise is beneficial for alleviating period pain.
The researchers found no evidence for an association between the two. However, this is a relatively small cross-sectional study, and it cannot clearly determine what effect exercise has on period pain. It did not specifically assess whether women exercised during their period, or whether they found that exercise helped to relieve menstrual pain. Also, the experience of pain is fairly subjective, which makes any accurate measure of it quite difficult.
Although this study didn’t find an association between exercise and the severity of period pain, regular exercise is advised for general wellbeing. If necessary, over-the-counter painkillers and anti-inflammatory drugs, such as ibuprofen, may be used in the short term to relieve period pain.
Where did the story come from?
This research was carried out by Dr H Blakey and colleagues at the University of Birmingham. It was published in the peer-reviewed medical journal The British Journal of Obstetrics and Gynaecology. The study received no external funding.
The story was reported well by the BBC, although this small cross-sectional study cannot definitely prove that exercise is “no aid” to period pain, as headlined.
What kind of research was this?
This cross-sectional study investigated whether exercise is beneficial for primary dysmenorrhea (period pain that is not associated with an underlying illness).
The researchers say that although some studies suggest there is anecdotal evidence that exercise can help severe period pain, other reports have shown no association between exercise and the severity of period pain.
Because of the cross-sectional structure of this study, which assessed women’s levels of exercise and whether they experienced period pain, it cannot be concluded that one affects the other. It did not specifically investigate whether women continue to exercise or abstain from exercise at the time of their period or if they perceive that exercise affects their pain.
A more reliable method of assessment would be a trial in which women who experience period pain are randomised to either exercise or no exercise and followed up to see what effect this has. However, this would be neither ethical nor practical.
What did the research involve?
The researchers distributed a questionnaire to 654 female university students between 18 and 25 years of age. The participants were not told the purpose of the study.
Participants were asked their age, ethnicity, height, weight and current smoking behaviour. They were also asked their age when they had their first period, how long their periods lasted, where in their menstrual cycle they were and whether they were on the contraceptive pill or had an intrauterine device.
To find out how much exercise the participants typically did, the researchers modified a questionnaire called the Godin Leisure-Time Exercise Questionnaire. This told the researchers how many times per week each participant did at least 30 minutes of exercise and what intensity of exercise that was.
The women rated their period pain using two scales. The visual analogue scale (VAS) asked women to rank their pain from zero (no pain) to 10 (extremely severe pain). The verbal multidimensional pain score (VMPS) asked women to grade the pain as none, mild, moderate or severe, based on how it affected their daily activities, its symptoms and how many painkillers they required.
So that the participants would not guess that the study was on period pain and exercise, the researchers also asked them questions about their mood.
When the researchers analysed the results they took into account body mass index, ethnicity, contraceptive pill use, smoking status and at what stage in the menstrual cycle participants were.
In total, 597 people responded to the questionnaires. From this number, a further 17 people were excluded as they were over 25 years, or had other conditions such as endometriosis, pelvic inflammatory disease, fibroids or ovarian cysts. These factors may have affected their experience of period pain (secondary dysmenorrhea).
What were the basic results?
The researchers found that 72.1% of the women experienced no pain or minimal pain. The other 27.9% experienced moderate to severe pain.
The researchers did not find any association between exercise and the severity of period pain the participants experienced. This was the case with both of the scales used to assess pain.
How did the researchers interpret the results?
The researchers concluded that exercise was not associated with less period pain, and say that “anecdotal beliefs that exercise is an effective treatment for primary dysmenorrhoea have prevailed for many years and while it might seem intuitively appealing to promote exercise as a treatment for menstrual disorders such as primary dysmenorrhoea, the findings from this study would not support such a view”.
This study found no association between exercise and the severity of period pain. However, the study had the following limitations.
- It required participants to recall the severity of their pain and their frequency of exercise. Pain is a very subjective experience, and it is difficult to measure accurately. What one person may perceive as mild pain, another may find severe. There is also a chance that the women gave overestimates of how much they exercised.
- The participants were university students, and may not represent the same socio-economic demographic as the general population.
- Although a general association between regular exercise and period pain was not found, it is difficult to conclude from this small cross-sectional study what effect exercise has on period pain. The researchers did not assess at what time in their menstrual cycle the women tended to exercise, and whether exercise had any effect while the participants were experiencing period pain. A trial situation in which women who experienced period pain were randomised to exercise or not would not be feasible.
Although this study does not find an association between exercise and period pain, taking regular exercise of more than 30 minutes a week is recommended to maintain a healthy lifestyle. If necessary, over-the-counter painkillers and anti-inflammatory drugs, for example ibuprofen, may be used in the short term to relieve period pain.