Podcast Summary: The Dr. Gabrielle Lyon Show – Women’s Training & The Menstrual Cycle: What the Science Actually Says | Lauren Colenso-Semple, PhD
Release Date: May 13, 2025
Introduction
In this enlightening episode of The Dr. Gabrielle Lyon Show, Dr. Gabrielle Lyon hosts Dr. Lauren Colenso-Semple, a distinguished researcher in female physiology from McMaster University. The conversation delves deep into the intricate relationship between women's hormonal cycles and their impact on fitness, muscle growth, and overall training effectiveness. Addressing prevalent myths and providing evidence-based insights, this episode is a must-listen for women aiming to optimize their training regimes without falling prey to misinformation.
Dr. Lauren Colenso-Semple’s Background
Dr. Colenso-Semple brings a wealth of knowledge to the conversation, holding a Ph.D. in Integrative Physiology, a master’s in Exercise Science from the University of South Florida, and a bachelor’s in Psychology and Nutrition. Her research primarily focuses on female physiology and muscle growth, addressing the significant gap in resistance training literature concerning women.
Dr. Colenso-Semple [02:29]: "When I decided to go back to school and get a master's degree and subsequently a PhD, I really wanted to help fill that gap because I think all scientists would agree that women are underrepresented in the literature."
Menstrual Cycle and Muscle Growth
A significant portion of the discussion centers around whether menstrual cycle phases influence muscle protein synthesis and, consequently, muscle growth. Dr. Colenso-Semple highlights that while hormonal fluctuations occur throughout the menstrual cycle, their direct impact on muscle growth is minimal.
Dr. Colenso-Semple [08:43]: "There isn't [evidence] that women should train related to their cycle."
Her research, including a study published in the Journal of Physiology in December 2024, found no significant differences in muscle protein synthesis or breakdown between different menstrual cycle phases in response to resistance exercise.
Dr. Colenso-Semple [28:08]: "We don't see a difference between muscle protein synthesis or muscle protein breakdown in either phase at rest or in response to Exercise."
Cycle Syncing: Myth vs. Science
Cycle syncing, the practice of tailoring training intensity based on menstrual cycle phases, has gained popularity on social media. Dr. Colenso-Semple critically examines this trend, emphasizing that it often leads to reduced training volume without scientific backing.
Dr. Colenso-Semple [11:12]: "Cycle syncing type models is encouraging women to plan to feel worse during a given period."
She advocates for autoregulatory training — adjusting workouts based on how one feels on any given day rather than adhering to pre-planned cycle-based modifications.
Oral Contraceptives and Performance
Oral contraceptives (OCs) are another focal point. Dr. Colenso-Semple discusses the impact of OCs on training outcomes, debunking the notion that they significantly hinder muscle gains or strength.
Dr. Colenso-Semple [22:28]: "Oral contraceptive use compared to naturally cycling individuals. There was no influence on hypertrophy, strength or power."
While some studies suggest minor variations, the consensus is that OCs do not have a clinically significant impact on muscle protein synthesis or performance outcomes.
Training Differences Between Men and Women
Addressing the common belief that men and women should train differently, Dr. Colenso-Semple clarifies that the fundamental principles of resistance training apply universally. The differences in muscle mass between sexes are primarily due to hormonal variations, particularly testosterone levels during puberty.
Dr. Colenso-Semple [36:06]: "It's about your starting point. Men experience a surge in testosterone during puberty... the relative gains are the same."
She emphasizes that while men typically possess more skeletal muscle mass, women can achieve comparable relative gains through consistent and progressive resistance training.
Fasted Training and Cortisol
The topic of fasted training often raises concerns about cortisol spikes and potential muscle catabolism. Dr. Colenso-Semple dismantles these fears by presenting evidence that fasted training does not negatively impact muscle mass or lead to unfavorable body composition changes.
Dr. Colenso-Semple [67:49]: "If anything, fasted training in some cases was a little bit better. But I don't think the effect is such that I'm a proponent of facet training."
She reiterates that the timing of nutrient intake is less critical than overall daily calorie and protein consumption, advocating for personal preference in training routines.
Nutrition: Protein, Carbs, and Meal Timing
Proper nutrition is paramount for optimizing muscle growth and maintaining body composition. Dr. Colenso-Semple advises focusing on total daily protein intake rather than specific meal timings.
Dr. Colenso-Semple [73:24]: "What's important is total overall protein intake and overall calorie intake. Apparently, the nutrient timing is not important."
She recommends a protein intake range of 1.2 to 1.6 grams per kilogram of body weight, ensuring that individuals meet their protein requirements to support muscle synthesis and overall health.
Menopause and Body Composition
Menopause brings about physiological changes, including muscle mass loss and fat redistribution. Dr. Colenso-Semple discusses how resistance training and proper nutrition can mitigate these changes.
Dr. Colenso-Semple [82:03]: "With aging in general, people tend to start to be less physically active... we see it in men as well, with age, increase in body fat and a loss of muscle mass."
She underscores the importance of maintaining an active lifestyle and adhering to resistance training principles to preserve muscle mass and manage body fat distribution during and after the menopausal transition.
Conclusion and Takeaways
Dr. Colenso-Semple encapsulates the conversation with the following key takeaways:
- Simplicity is Key: Focus on consistent, challenging resistance training and adequate protein intake.
- Debunk Myths: Menstrual cycles and oral contraceptives do not necessitate drastic changes in training routines.
- Individualization Over Generalization: Tailor training programs based on personal preferences and how one feels, rather than adhering to prescriptive models like cycle syncing.
- Nutrition Matters: Prioritize total daily protein and calorie intake over specific meal timings or macronutrient ratios.
- Stay Active Through Life Transitions: Resistance training remains crucial for muscle preservation and metabolic health, even during menopause.
Dr. Colenso-Semple [79:35]: "Keep it simple. The basics that we've talked about here today are what's important."
Dr. Lyon concludes by reinforcing the message that women's physiology is not a limitation but an asset when it comes to building muscle and maintaining health.
Dr. Gabrielle Lyon [83:38]: "Your physiology as a woman is not a limitation. The science is clear. You can train consistently, lift heavy and build muscle year round."
This episode serves as a beacon of evidence-based information, empowering women to approach their training with confidence and clarity, free from the constraints of unfounded myths and societal misconceptions.