Evidence for Periodizing Strength and/or Endurance Training According to Menstrual Cycle Phases to Optimize Female Athlete Performance Is Lacking

ABSTRACT Periodizing and programming strength and endurance training according to the phases of the menstrual cycle has been recommended in popular and social media. The approach is based on the idea that the nonreproductive actions of female sex hormones like estradiol and progesterone can be “taken advantage of” to enhance or optimize training. Female sex hormone concentrations, which fluctuate across the menstrual cycle, influence physiological processes acting on muscle, nervous, epithelial, and connective tissues, although sometimes being associated with adverse symptoms. These changes in sex hormone concentrations are suggested to influence strength and endurance training outcomes to some extent. However, at present, research does not support the idea that periodizing or programming strength or endurance training according to the menstrual cycle confers additional benefits over more traditional approaches to strength or endurance training. The purpose of this article is to critically review the scientific literature regarding “period-periodized” training to improve strength and/or endurance performance and to evaluate the approach from a strength and conditioning research perspective. This review encompasses both strength and endurance training as both training modes are included in global exercise recommendations, as well as the training programs of most competitive athletes.