As a coach, particularly a male coach, it can be difficult to start talking to your athletes about their menstrual cycles. But if you are able to start the conversation by looking at the menstrual cycle as any other performance metric such as sleep, nutrition, or hydration, it becomes easier to start the conversation.
You will probably find that many of your athletes appreciate this and feel more comfortable telling you about how their cycles affect them. Explain to them how you would use their cycle data to understand their individual patterns of symptoms, their adaptations to training and performance across their cycles, and that it can become a key piece of the performance puzzle. This is what could normalise the conversation between coach and athlete.