PURPOSE: More than half of athletes report detrimental effects on exercise caused by their menstrual cycle. However, the specific menstrual cycle symptoms experienced by exercising women, and a means to quantify occurrence and prevalence of symptoms is lacking. Therefore, we aimed to; identify the most common menstrual cycle symptoms experienced; devise a way to quantify symptoms; and to ascertain the impact of that they have on both exercise and work behaviours. METHODS: 6,812 women using an exercise tracking app of a reproductive age who were not using combined hormonal contraception from 7 geographical regions (Brazil, n=1,288; France, n=1,911; Germany, n=1,178; Spain, n=1,204; UK & Ireland, n=2,311; and USA, n=2,479) completed a 39-part questionnaire, translated and localised to each geographical region. The questionnaire captured current and previous exercise behaviours; current menstrual status; the presence of, and frequency of symptoms; use of medication for symptoms; effects of the menstrual cycle on exercise and work behaviours; and hormonal contraception use. A menstrual cycle symptom score (MCSS) was defined based on the presence and frequency of 18 commonly reported symptoms.
RESULTS: The most frequent symptoms reported included mood changes/anxiety (90.6%), tiredness/fatigue (86.2%), stomach cramps (84.2%), and breast pain/tenderness (83.1%). Participants in Germany and France had a significantly lower MCSS and reported fewer MCSS than those in Spain, the UK & Ireland, the USA and Brazil (p<0.05). After controlling for BMI, training volume and age, those participating in running (p=0.038), swimming (p=0.033), cycling (p=0.001), team sports (p=0.027), racket sports (p=0.010), and dance (p=0.001) had a lower MCSS. While participation in gym-based activities (p=0.023) and weight training (p<0.005) were associated with a higher MCSS. Total MCSS was correlated with a greater need to miss or change training (r=0.44; p<0.0005) and work/academic absenteeism (r=0.31; p=0.001). CONCLUSIONS: Menstrual cycle symptoms are common in exercising women and can have a detrimental effect on elements of health and wellbeing. The derivation of a MCSS enables an easy way to quantify menstrual cycle symptoms. Future research needs to investigate risk factors and non-pharmacological treatment options.