Exercise does not help to alleviate period pain, despite it being commonly recommended for women with monthly symptoms, say researchers.
A study of more than 650 university students reported in BJOG found 28% had moderate to severe period pain.
But Birmingham University researchers said they found no link with the amount of exercise the participants did.
GPs said women should be encouraged to do exercise regardless but drugs are available for those with period pain.
The study authors said beliefs about exercise being an effective treatment for bad period pain had persisted for years.
It is a common problem and people usually self-medicate
Professor Steve Field, Royal College of GPs
They carried out a questionnaire among 18 to 25-year-olds to find out what age they started their period, how often they had periods, what contraception they used, and whether they had children or had any conditions such as endometriosis or fibroids.
The students were also asked what type of exercise they did and how often as well as other general lifestyle questions.
Responses showed that 72% had no or very little period pain but 28% had moderate to severe pain with their monthly cycle.
After taking into account mood, ethnicity, weight, smoking, and use of the contraceptive pill, they found no link with how much exercise a woman did and whether she suffered from period pain, or how bad her pain was.
'Anecdotal beliefs'
Researcher, Dr Amanda Daley concluded that more research was needed before women are told that exercise will reduce of alleviate period pain.
"Anecdotal beliefs that exercise is an effective treatment have prevailed for many years and while it might seem intuitively appealing to promote exercise as a treatment for menstrual disorders, the findings from this study, along with many others, would not support such a view.
"Of course there are many other important health reasons for encouraging women to be physically active and exercise performed in moderation is unlikely to be harmful."
Royal College of GPs chairman Professor Steve Field said women with period pain should do what works for them and exercise might make them feel better in general.
"It is a common problem and people usually self-medicate.
"Some exercise is good for you of course but the main treatment for period pain is the contraceptive pill."
尽管建议有痛经的妇女做锻炼,但是它对缓解痛经没有帮助,研究人员说。
650多所大学学生的调查研究在BJOG上报告,发现28%的学生有中到重度的痛经。
但是伯明翰大学研究员说,他们发现参加者的痛经与所做的运动量没有关联。
医生说,要不是经期疼痛,不管是否使用药物,应该鼓励妇女做锻炼。
这项研究的创始人说,锻炼是重度经期疼痛妇女有效治疗的说法持续了数年。
他们完成了在1-25岁女孩中 "那是一个常见的问题做的一次问卷调查发现她们 而且人们通常自己月经的初潮年龄,月经 治疗"
间隔时间,她们使用的避孕 皇家医科医师学院史蒂方法,以及她们是有孩子还 夫菲尔德教授
是处于像子宫内膜异位或子宫平滑肌瘤状态。
学生们还被提问了她们所做锻炼的方式以及多长时间锻炼一次和其它的生活方式问题。
调查显示,72%的学生没有痛经或仅有轻微疼痛,但是28%的学生在经期,有中到重度疼痛。
把情绪,种族,体重,吸烟,和避孕药的使用考虑在内之后,他们发现女性患痛经或她的疼痛的严重性与她们的运动量没有关联。
'轶事信仰'
研究员阿曼达达类做出结论,在通知女性运动将减少缓解经期疼痛之前,我们需要作更多的研究。
运动是一种有效的治疗的轶事信仰已经盛行很多年,而且似乎是直观地呼吁增加运动,作为一种月经不调治疗,这种研究的调查结果以及其它的研究结果不支持这种观点。
"当然还有许多其它重要的健康原因,鼓励妇女进行中等量的体育体操活动对身体是不会有害的。"
皇家医科医师学院主任教授史蒂夫菲尔德说,经期疼痛的妇女应该做使她们总体上感到舒服的工作和运动。
"那是个常见问题而且人们通常自己治疗。"
"当然有些运动有益于健康,但是痛经的主要治疗是使用避孕药。"