Final answer:
Low energy availability can lead to irregular or absent menstrual cycles due to the body prioritizing survival over reproduction.
Step-by-step explanation:
Low energy availability can have an effect on menstrual cycles by leading to irregular or absent menstrual cycles. When there is insufficient energy for the body, it prioritizes survival over reproduction. This can disrupt the hormonal balance required for ovulation and proper menstrual cycle functioning. Factors such as inadequate nutrition, stress, and certain health conditions can contribute to low energy availability and impact menstrual cycles.