In this episode of unPAUSED, Dr. Mary Claire Haver talks with Dr. Jennifer Garrison, a neuroscientist and entrepreneur, about why the ovary should never have been labeled a purely reproductive organ. Dr. Garrison explains that ovaries function like a second brain in the body, sending and receiving chemical signals to nearly every tissue system including the heart, bones, brain, immune system, and metabolism. She walks through her research on the hypothalamus and the brain ovary signaling network, describing how inflammation in this part of the brain may be one of the earliest drivers of aging across the whole body.

The conversation covers why the ovary ages roughly two and a half times faster than the rest of the body, a gap that helps explain the health span difference between women and men. Dr. Garrison and Dr. Haver discuss how poor ovarian function shows up across a woman's life, not only at menopause, contributing to conditions like polycystic ovarian syndrome, infertility, early menopause, depression, metabolic disease, and autoimmune disease. They also unpack why autoimmune conditions rise sharply after menopause and why women's immune systems respond differently to viruses than men's.

Guest links:

Jennifer Garrison, PhD (LinkedIn)

Jennifer Garrison (X)

Jennifer Garrison (Bluesky)

Jennifer Garrison (X Prize)
Jennifer Garrison (The Institute)

Books

“The New Perimenopause,” by Dr. Mary Claire Haver

“The New Menopause"⁠ by Dr. Mary Claire Haver

For full show notes, please click here.

In this episode of unPAUSED, Dr. Mary Claire Haver continues her conversation with exercise physiologist and nutrition scientist Dr. Stacy Sims, moving from what does not work to what actually does for women in perimenopause and menopause. They cover why strength training, not endless cardio, is one of the most powerful tools women have for protecting muscle, bone, and brain health at midlife, and Dr. Sims walks through exactly how to structure a 20 minute strength session for maximum benefit.

The conversation turns to creatine, including why women between 18 and 65 see some of the strongest benefits for brain and heart health, proper dosing, and why timing and mixing matter for bioavailability. Dr. Sims and Dr. Haver also discuss why distance runners can still develop osteoporosis despite years of training, and how chronic under fueling and calcium loss play a role.

Guest links:

Dr. Stacy Sims

Dr. Stacy Sims (Facebook)

Dr. Stacy Sims (YouTube)

Dr. Stacy Sims (Instagram)

Stacy T. Sims, PhD (LinkedIn)

Dr. Stacy Sims Newsletter

Dr. Stacy Sims Microlearning Course

Books

“The New Perimenopause,” by Dr. Mary Claire Haver

“The New Menopause"⁠ by Dr. Mary Claire Haver

“Next Level: Your Guide to Kicking Ass, Feeling Great, and Crushing Goals Through Menopause and Beyond,” by Dr. Stacy Sims

“ROAR: How to Match Your Food and Fitness to Your Unique Female Physiology for Optimum Performance, Great Health, and a Strong, Lean Body for Life,” by Dr. Stacy Sims

In this episode of unPAUSED, Dr. Mary Claire Haver sits down with exercise physiologist and nutrition scientist Dr. Stacy Sims to unpack why so much fitness and diet advice built on male physiology leaves women confused about why the scale will not move, and why weight loss can feel so much harder for women than for men on the exact same plan. Dr. Sims, author of Roar and Next Level, a former professional cyclist who has taught and coached at Stanford, breaks down why women following the same diet and training program as their male partners often end up tired and stuck rather than leaner and fitter.

The conversation covers the biological reasons women conserve fat in a calorie deficit, how female circadian rhythm differs from male circadian rhythm, and why eating within an hour of waking helps regulate cortisol and appetite hormones like ghrelin and peptide YY. Dr. Sims explains why fasted workouts can backfire for women, why front loading calories earlier in the day supports better metabolic outcomes, and why time restricted eating works with a woman's biology in ways that intermittent fasting often does not.

Guest links:

Dr. Stacy Sims

Dr. Stacy Sims (Facebook)

Dr. Stacy Sims (YouTube)

Dr. Stacy Sims (Instagram)

Stacy T. Sims, PhD (LinkedIn)

Dr. Stacy Sims Newsletter

Dr. Stacy Sims Microlearning Course

Books

“The New Perimenopause,” by Dr. Mary Claire Haver

“The New Menopause"⁠ by Dr. Mary Claire Haver

“Next Level: Your Guide to Kicking Ass, Feeling Great, and Crushing Goals Through Menopause and Beyond,” by Dr. Stacy Sims

“ROAR: How to Match Your Food and Fitness to Your Unique Female Physiology for Optimum Performance, Great Health, and a Strong, Lean Body for Life,” by Dr. Stacy Sims