A study of university students has found that exercise is not the most effective cure for period pain, despite this being widely believed for many years.
Researchers from Birmingham University studied more than 650 students, with results showing no link between levels of pain and exercise.
Of those studied, 28% reported suffering moderate to severe monthly pain, while the remaining 72% said they felt no pain, or very little.
The 18-25 year-old women surveyed were asked about when they started their period, how often they had them, contraception use, whether they suffered from endometriosis or fibroids and whether they had children.
Other factors such as what type of exercise they did and how much, as well as weight, smoking and mood - which can have an effect on levels of pain - were considered.
The conclusion was that there was no link between exercise and pain reduction, although the researchers said belief in the effects had existed for years.
GPs said women should still be encouraged to exercise, but said that drugs were available for the management of pain.
The results of the study were published in BJOG: An International Journal of Obstetrics and Gynaecology.