The groundbreaking book that revolutionized exercise nutrition and performance for female athletes is now freshly updated.

"Women are not small men. Stop eating and training like one."


In ROAR, exercise physiologist and nutrition scientist Stacy T. Sims, PhD, teaches you everything you need to know to adapt your nutrition, hydration, and training to work with your unique female physiology rather than against it.

By understanding your physiology, you’ll know how best to adapt your lifestyle and build routines to maximize your performance, on and off the sports field. You’ll discover expert guidance on building a rock-solid foundation for fitness and everyday life with tips for determining your high-performance body composition, gaining lean muscle, and nailing your nutrition. Because a woman’s physiology changes over time, you’ll also find full chapters devoted to pregnancy and menopause.

This revised edition includes a wealth of new research developments, expanded recommendations based on those findings, and updates to reflect the changing landscape of women’s sports.

No matter your activity—Olympic lifting, general fitness, endurance, or field sports—this book will empower you with the personal insight and knowledge you need to be in the healthiest, fittest, strongest shape of your life.

Where can I buy ROAR?


Stacy T Sims PhD

Stacy T Sims, PhD, is a forward-thinking international exercise physiologist and nutrition scientist who aims to revolutionize exercise nutrition and performance for women. She has directed research programs at Stanford, AUT University, and the University of Waikato, focusing on female athlete health and performance and pushing the dogma to improve research on all women. Her first version of ROAR, released in 2016, explained sex differences in training and nutrition across the lifespan and challenged the existing dogma for women in exercise, nutrition, and health. This paradigm shift is the focus of her famous "Women Are Not Small Men” TEDx talk. Her revised edition of ROAR (2024) incorporates all the advances in science over the last eight years.

Selene Yeager

Selene Yeager has authored, co-authored, and contributed to more than two dozen book titles and her work has appeared in numerous media including Details, Shape, O, the Oprah Magazine, Bicycling, Men’s Health, Women’s Health, Marie Claire, Better Homes & Gardens, Good Housekeeping, Runner’s World, More, Cooking Light, and Cosmopolitan. When not writing and podcasting, Yeager lives what she writes as a NASM-certified personal trainer, Precision Nutrition Certified Nutrition Coach, USA Cycling certified coach, off-road bike racer, and former All-American Ironman triathlete.

Differences between the 2016 and 2024 versions

I went through and updated all the research to reflect what has been done and determined over the past 8 years.

This includes additional information on hormonal contraceptives, why to track your menstrual cycle, what is RED-S/LEA vs under-recovery, expanded the recommendations to reflect the new position stands for active women; geared the recommendations to the everyday active woman, not elite athletes; updated the biohacking section to include the newest trends and if they are worth it or not- heart rate variability, sleep/sleep tracking, continuous glucose monitors, urinary analysis, genetic testing (eg 23andMe).

Plus, I updated exercises, case studies, and nutrition makeovers.

More Specifically

Don't want to read about them all?  Listen to me talk about the differences.

The differences between versions

Stacy and Selene Chat About the Revised Edition of ROAR


Where can I buy ROAR?

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A note about the research scope of ROAR:

Our goal is to present women with knowledge about their unique physiology as it pertains to exercise, training, and their performance.

There are limitations in the science. Existing training, nutrition, and performance science has been conducted largely on people of the female and/or male sex who are not using masculinizing and/or feminizing hormone therapy. There is a need for exercise, sports nutrition, and performance research on trans women and trans men who may have a puberty trajectory that has been modified with the use of exogenous hormone therapy, as well as on adults who have started using gender affirming therapies later in life.

Currently, the majority of transgendered research is on the health and medical impacts of those therapies and has not reached the sport and exercise sciences realm. We will be watching the research landscape as it evolves and include as much performance information for as many women as possible.