New research shows that real-time daily tracking, rather than memory-based surveys, reveals the true timing, frequency, and performance impacts of menstrual and contraceptive-related symptoms in elite athletes.
Study: Menstrual cycle or hormonal contraceptive related symptoms in elite female athletes from retrospective self-questionnaires and daily monitoring: impact on well-being and objective performance metrics. Image credit: PeopleImages/Shutterstock.com
In a recent study published in Frontiers in Sports and Active Living, researchers assessed hormonal contraceptive (HC)- and menstrual cycle (MC)-related symptoms in elite female athletes and their impact on performance and well-being.
The MC, characterized by cyclical changes in sex hormones, may influence sporting performance and well-being. A recent study reported that MC-related symptoms were common in female athletes, with 24 % to 100 % of athletes experiencing psychological or physical symptoms. Negative symptoms of the MC impact well-being, training, and performance.
HCs, particularly oral contraceptives, are commonly used in athletic populations and are sometimes prescribed for MC-related symptoms. Nevertheless, HCs are also associated with adverse effects, including mood changes, tiredness, and headache. A better understanding of menstrual symptoms during the MC and continuous or intermittent HC use is required to improve support for athletes.
Researchers also sought to understand whether different methods of symptom reporting, retrospective versus daily monitoring, produce different conclusions, given that retrospective questionnaires may be affected by memory bias and daily monitoring may underreport milder symptoms due to reporting fatigue.
Comparing daily and retrospective symptom tracking
In the present study, researchers investigated the symptoms associated with MC or HCs in elite athletes and their associations with sporting performance and well-being. The study included menstruating (MC) athletes and athletes using HCs. A (retrospective) questionnaire collected data on demographics, menstrual history, training, and cycle-related effects on performance.
Athletes reported the most frequent psychological or physical symptoms, i.e., occurring at least once a cycle in > 50 % of cycles. Further, they completed a daily questionnaire for six months, reporting on their symptoms and well-being (sleep quality, mood, and fitness). Reporting methods were aligned by defining “frequent symptoms” in daily monitoring as those occurring in more than half of an athlete’s tracked cycles,
For MC athletes, cycles were categorized into menstruation (bleeding), pre-bleeding, and in-between phases. Moreover, each cycle was stratified based on duration.
A regular cycle had a length of 21 to 35 days, with a variation of fewer than seven days between cycles; other cycles were defined as irregular. For athletes on intermittent HC, the active hormonal and break phases were determined. For those on continuous HC, cycle lengths were fixed at 28 days, with no further phase division. For cyclists and football players, objective performance metrics were derived from sensors used during training. For cyclists, normalized power output was calculated.
For football players, the total distance covered and the distance covered at different speeds were measured. The number and proportion of athletes frequently experiencing symptoms were estimated, and the differences between groups were compared. Additionally, differences in symptom frequency between phases were assessed. The associations of symptoms with well-being and performance metrics were evaluated.
Symptoms lower well-being and slow high-speed performance
The study included 108 elite athletes participating in cycling, rowing, skiing, football, swimming, wrestling, and triathlon. Sixty-three participants were MC athletes, and 45 were HC athletes, including six continuous HC users. In total, data on 554 complete cycles were collected during the follow-up, with an average of five cycles per athlete. On average, athletes reported 3.5 symptoms as frequent in the retrospective questionnaire.
The MC group reported significantly more symptoms than HC athletes. Among MC athletes, pelvic pain (57.1 %) was the most frequently reported retrospective symptom, followed by tiredness and breast pain. In contrast, mood swings and tiredness were the most common in HC athletes. On average, 2.3 symptoms were regularly reported by all athletes in the daily questionnaire, with MC athletes reporting significantly more symptoms than HC athletes.
In the MC group, bloating, tiredness, and pelvic pain were the most common symptoms. In the HC group, the most frequent symptoms were tiredness, soreness, bloating, and pelvic pain. Pelvic pain in the HC group occurred less frequently than in the MC group, consistent with the more stable hormonal profile associated with HC use.
In the retrospective questionnaire, nearly 90 % of athletes regularly experienced at least one symptom, compared to about 65 % of athletes in the daily questionnaire. At least one symptom was reported for a mean of 4.28 days in a regular MC compared to 3.29 days in an irregular MC. On average, 3.29 and 2.59 symptomatic days were reported in continuous and intermittent HC cycles.
The proportion of symptomatic days in a regular MC was significantly greater in the menstruation phase, while symptoms were more frequent in the pre-bleeding phase. In an irregular cycle, symptoms were more prevalent in the menstruation phase, while they were more frequent during the in-between phase. In the continuous HC cycle, 11.7 % of the time was spent with one or more symptoms. In the intermittent HC cycle, symptoms were more frequent during the break phase.
Symptoms were negatively correlated with well-being, with better scores across all three indicators on symptom-free days. There were no significant differences in the total distance covered or distance covered at low speeds (< 13 km/h) for football players and the normalized power output for cyclists between symptomatic and symptom-free days. However, football players covered significantly more distance at higher speeds (> 13 km/h) when they were symptom-free.
Menstrual symptoms meaningfully affect athlete health and output
The study found significant differences in the prevalence of menstrual symptoms between retrospective and prospective questionnaires. MC athletes reported significantly more symptoms than HC athletes in both questionnaires.
In the MC group, regular cycles were associated with more symptomatic days than irregular cycles. However, these differences require further interpretation, as irregular cycles still followed similar symptom timing patterns. Moreover, symptoms had a significant impact on high-speed running among football players and the well-being of all athletes.
Retrospective methods may overestimate symptom prevalence due to memory bias. In contrast, daily monitoring, despite the potential for underreporting mild symptoms, provides a more accurate day-to-day picture of when symptoms occur.
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