Are Women Small Men? | Dr Lauren Colenso-Semple

Women are told to change their lifting, cardio, protein and even meal timing depending on their cycle phase. Dr Lauren Colenso-Semple has measured those hormones across many cycles in many women, and she has published some of the key research testing whether cycle phase changes how muscle responds to training. In this episode, she and Cliff look at what the evidence supports, what it doesn't, and why goal-led, individualised training beats a hormone calendar. In this episode we cover Why "women are not small men" started as a call for better research and turned into rigid, fear-based rules How much research in women actually exists in weight loss, endurance and resistance training Why the textbook 28-day cycle with ovulation on day 14 rarely matches real life Why sex differences in strength and muscle gain shrink once people are trained How to auto-regulate training on a bad day without skipping the session Wearables, readiness scores and handing your judgement over to an app The luteal phase protein claim, and how it stacks one untested mechanism on another Fasted training, low-carb diets and the fragility narrative aimed at women Chapters 00:00 Intro 01:12 Catching up after the Austin conference 03:04 Are women just small men? 04:05 When empowerment becomes disempowering 05:37 Why it took so long to study women 08:45 How much research in women do we have? 11:00 Cycle syncing and the 28-day myth 14:21 Lean mass, training status and sex differences 17:23 Train for your goal, not your fibre type 18:16 Overcomplication and selling what you can't measure 20:55 Life stages, PCOS and lived experience 24:55 Do you need lived experience to be an expert? 30:10 Consistency beats optimisation 35:13 How to auto-regulate training 40:55 Objective vs subjective performance 43:18 Wearables, readiness scores and AI 48:00 Tracking your cycle as one variable among many 50:41 Dogma, branding and changing your mind 54:30 Cycle-specific nutrition: the luteal protein story 59:38 Fasted training and low energy availability 1:01:39 Should women fast or go low carb? 1:05:38 The optimisation fallacy 1:09:05 How adaptable humans are 1:13:37 When life gets in the way 1:17:12 "Don't do this" messaging: zone 2, HIIT and running 1:19:44 Lauren's take-home message 1:21:32 The Practitioner's Roadmap About Dr Lauren Colenso-Semple Lauren is a muscle physiology researcher who completed her PhD at McMaster University, focused on exercise physiology, endocrinology and sex-based differences in muscle growth. She is co-owner of and a reviewer for the MASS Research Review and a regular voice on the Iron Culture podcast. Find her on Instagram at @drlaurencs1 and at MASS Research Review . Links mentioned in this episode MASS Research Review: https://www.massresearchreview.com/ Iron Culture podcast: https://ironculture.libsyn.com/ Colenso-Semple et al. (2023), umbrella review on cycle phase and resistance training: https://doi.org/10.3389/fspor.2023.1054542 Colenso-Semple et al. (2025), cycle phase and muscle protein synthesis: <a href="https:/