Mechanisms Underlying Menstrual Cycle Effects on Exercise Performance: A Scoping Review

This scoping review aims to provide a comprehensive overview of biological mechanisms underlying the menstrual cycle's ' s impact on various performance-determining anatomical and physiological parameters. It is intended to identify the various proposed vital concepts and theories that may explain performance changes following hormonal fl uctuations. The review was performed following the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews protocol. A framework of six groups was built such as skeletal muscle physiology, muscle damage, tendons and ligaments, neuromuscular control, cardiovascular system, and exercise metabolism to cluster studies thematically and to specify the concept of " performance. " Original research studies published between 1970 and 2021 that were conducted with a naturally menstruating population were considered. Changes in performance regarding the menstrual cycle phase were crucial for inclusion. Topic-specific fi c reviews and systematic reviews were included if they addressed the impact of female steroid hormones on any structure or part of the human body. The review indicates that the impact of estrogen and progesterone is primarily responsible for observed changes in athletic performance during the menstrual cycle. Estrogen seems capable of fostering protein synthesis, diminishing collagen metabolism, preventing muscle damage due to its antioxidant effects, and restraining inhibitory, while promoting excitatory, control by interacting with neurotransmitters. Progesterone is assumed to increase thermoregulation and enhance ventilatory drive by interacting with hypothalamic pathways and may further amplify inhibitory control by interacting with neurotransmitters. The female steroid hormones and the endocrinologic system collaborate in complex interrelationships with biological systems to maintain homeostasis. However, proposed mechanisms are often derived from animal studies and studies conducted in vitro and still remain to be proven true in the human regularly menstruating population. In the future, it is crucial to rely on studies that followed the methodology for cycle monitoring recommendations thoroughly. Otherwise, it is not possible to determine whether hormonal fl uctuations cause observed changes in performance or not.