Menstrual Cycle Dynamics and Their Influence on Physical Activity for College Going Recreational Athletes

The menstrual cycle is a crucial biological rhythm typically lasting 21 to 35 days, averaging 28 days, is vital for female recreational athletes. Increasingly, women in sports are recognizing menstrual cycle impact on performance due to hormonal fluctuations. Sensitivity to these changes varies, potentially affecting exercise tolerance and energy levels during training and competition. Recognizing these dynamics is crucial to optimize athletic performance with tailored interventions, considering the menstrual cycle's impact on the female body.
To evaluate the impact of the menstrual cycle on physical activity, a self-administrative questionnaire was formulated in three stages: establishing the questionnaire's scope through reviewing literature, determining questionnaire components by consulting participants and experts feedback, and verifying its content validity index (CVI) with the input of eight experts using delphi method. A final draft of 15 questions was then formulated with Scale level-CVI (S-CVI) of 0.98. All 15 questions had an item level CVI (I-CVI) of 0.87 to 1. Finally, the questionnaire was distributed to 362 female recreational athletes through online google form.The result of the study found that 28.5% reported menstrual cycle irregularity, 66.5% were educated about menstrual cycle effects on athletics, 75.3% recognized energy fluctuations, and 52.4% perceived menstrual cycle impact on physical activity. Additionally, 56.8% experienced motivation changes, 63.2% noticed strength/endurance alterations, and 68.7% were affected by menstrual discomfort. Lastly, 51.5% used psychological strategies to cope with menstrual cycle challenges during activities.The study reveals diverse experiences among female recreational athletes regarding menstrual cycle irregularity, its impact on physical activity, and recognition of energy level fluctuations. While some face irregularities, many acknowledge the menstrual cycle's influence on activity and recognize energy fluctuations across phases. These findings emphasize the necessity of tailored support and education to help athletes manage menstrual cycle-related challenges and enhance performance.

月经周期（menstrual cycle）是一种关键的生物节律，通常持续21至35天，平均时长为28天，对于女性休闲运动员而言至关重要。由于激素波动，越来越多的女性运动员开始意识到月经周期对运动表现的影响。个体对这些激素变化的敏感度存在差异，这可能会在训练与比赛期间影响运动耐量与能量水平。考虑到月经周期对女性身体的影响，明晰这些变化规律对于通过个性化干预手段优化运动表现至关重要。

为评估月经周期对身体活动的影响，本研究通过三个阶段编制了一份自填式问卷：首先通过文献综述确定问卷的研究范围，随后咨询参与者与专家意见以明确问卷条目，最后采用德尔菲法（Delphi method）邀请8位专家对问卷的内容效度指数（content validity index, CVI）进行验证。最终形成包含15个条目的问卷初稿，其量表水平内容效度指数（Scale level-CVI, S-CVI）为0.98；所有15个条目的条目水平内容效度指数（item level CVI, I-CVI）介于0.87至1之间。最终，研究团队通过在线谷歌表单（Google Form）将问卷发放给362名女性休闲运动员。

研究结果显示，28.5%的受访者存在月经周期不规律的情况；66.5%的受访者了解月经周期对运动表现的影响；75.3%的受访者察觉到自身能量水平的波动；52.4%的受访者感知到月经周期对身体活动的影响。此外，56.8%的受访者出现过运动动机的变化；63.2%的受访者注意到自身力量/耐力的改变；68.7%的受访者受到经期不适的影响。最后，51.5%的受访者会在运动过程中采用心理策略来应对月经周期相关的挑战。

本研究揭示了女性休闲运动员在月经周期不规律、月经周期对身体活动的影响以及对能量水平波动的认知等方面存在多样化的体验。尽管部分运动员存在月经周期不规律的问题，但多数群体认可月经周期对运动活动的影响，并能察觉到不同周期阶段的能量波动。上述研究结果强调，为运动员提供个性化支持与相关教育，以帮助其应对月经周期相关挑战并提升运动表现，具有重要必要性。