For decades, women have been given health, fitness and nutrition advice based largely on research conducted on men.
This week on Performance People, Georgie speaks to exercise physiologist and nutrition scientist Dr Stacy Sims, the woman behind the phrase: “Women are not small men.”
This is a mythbusting conversation about the gender data gap in health and performance: why women need to lift heavy, why fasted training may not work the way many women think it does, why menstrual cycles should be understood rather than treated as a complication, and how the rise of GLP-1 weight-loss drugs is creating a new set of concerns around strength, body image and long-term health.
Stacy also explains that AI is likely reinforcing outdated male-centred health advice, and how her new project, Collective X, is aiming to close the female data gap through better research, better methodology and better tools for women.
FAQs
Who is Dr Stacy Sims?
Dr Stacy Sims is an exercise physiologist and nutrition scientist known for her work on female physiology, training, nutrition and the phrase “women are not small men.”
What does “women are not small men” mean?
It means women’s bodies should not be treated as smaller versions of men’s bodies. Female physiology has distinct hormonal, metabolic, cardiovascular and muscular differences.
Why is male data a problem in health and fitness research?
Much of the research behind training, nutrition and health advice has historically been conducted on men and then generalised to women, which can lead to advice that does not properly reflect female physiology.
Should women train the same way as men?
Dr Stacy Sims argues that women should not simply follow scaled-down male training plans. Training should account for female physiology, including differences in muscle fibre type, recovery, hormones and life stage.
Should women lift heavy weights?
Yes. Dr Sims explains that heavy lifting is important for strength, power, muscle, bone health and long-term performance.
Is fasted training good for women?
Dr Sims argues that fasted training can be counterproductive for many women because of its effects on cortisol, appetite hormones, energy availability, lean mass and recovery.
Do women need more protein?
Protein needs should be considered in relation to body weight, activity level and goals. Dr Sims stresses that many active women under-eat protein and that protein supports muscle, satiety and body composition.
Should women change their training around their menstrual cycle?
Dr Sims says women do not need to completely change training every week based on generic cycle rules. Instead, they should track their own patterns and adjust based on how they respond individually.
Are wearables accurate for women?
Dr Sims argues that many wearables are still built on male-centred algorithms and can misread normal female physiological changes, especially around ovulation, heart rate variability, temperature and recovery.
Why might AI make women’s health advice worse?
Because AI tools often learn from existing published information, Dr Sims warns they may repeat older male-centred data and outdated health advice unless female-specific evidence is built into the system.
What does Dr Stacy Sims say about GLP-1 weight-loss drugs?
She says GLP-1 drugs can be powerful and useful when prescribed appropriately, but she is concerned about microdosing for vanity weight loss, body image effects and the loss of lean mass without proper lifestyle support.
________________________________
The views and opinions expressed on Performance People are those of the guests and hosts, and do not necessarily represent the views of ainslie + ainslie, J.P. Morgan Private Bank, or any affiliated organisations.
This podcast is produced by Gameface Limited and is intended for general information and entertainment purposes only.
© Gameface Limited 2026. All rights reserved.
Connect with Performance People
Hit subscribe today for the latest.
🎧 Spotify/Apple Music
http://www.performancepeoplepodcast.com/
https://www.instagram.com/performance.people/
________________________________
The views and opinions expressed on Performance People are those of the guests and hosts, and do not necessarily represent the views of ainslie + ainslie, J.P. Morgan Private Bank, or any affiliated organisations.
This podcast is produced by Gameface Limited and is intended for general information and entertainment purposes only.
© Gameface Limited 2026. All rights reserved.
Hosted on Acast. See acast.com/privacy for more information.
UK