Exercise-induced menstrual cycle changes. A functional, temporary adaptation to metabolic stress

Area of Science:

• Sports Medicine
• Reproductive Endocrinology
• Exercise Physiology

Background:

• Chronic exercise is recognized to impact the menstrual cycle in female athletes.
• The precise incidence of menstrual cycle alterations is unclear due to limited normative data and unaddressed metabolic costs of training.
• Secondary amenorrhea requires more than exercise alone, often necessitating additional metabolic stressors.

Purpose of the Study:

• To explore the incidence and nature of exercise-related menstrual cycle alterations in athletes.
• To investigate the role of metabolic cost and stressors in exercise-induced menstrual dysfunction.
• To re-evaluate exercise-related menstrual changes as a potential adaptive energy-conserving strategy.

Main Methods:

• Review of existing literature on exercise and menstrual function.
• Analysis of factors contributing to menstrual cycle alterations in athletic populations.
• Comparison with theories of metabolic arrest in other organisms.

Main Results:

• Secondary amenorrhea is not readily induced by exercise alone; additional metabolic stressors are typically involved.
• Short or inadequate luteal phase cycles can occur even with moderate running distances.
• Exercise-induced menstrual changes are often temporary and reversible upon training cessation.
• These alterations may be viewed as a functional adaptation for energy conservation.

Conclusions:

• Exercise-related menstrual cycle changes in athletes may represent an adaptive energy-conserving strategy.
• This phenomenon aligns with the concept of metabolic arrest observed in other species.
• Understanding these adaptations is crucial for managing female athletic health and performance.