Before we dive in, I want to encourage you to learn more about Brady Holmer and his work. He's the founder of the Physiologically Speaking newsletter and editor of Run Long, Run Healthy. You can also check out his e-book, VO₂ Max Essentials, which breaks down one of the most important health metrics we discuss in this episode.  Here are the links:  Physiologically Speaking: https://bradyholmer.substack.com  Run Long, Run Healthy: https://www.runlongrunhealthy.com  VO₂ Max Essentials e-book and website: https://www.bradyholmer.com/  Now, onto the episode...  Hi everyone. I’m Barbara and this is Age Better.  We often focus on numbers like weight, cholesterol, or blood pressure—but what if there were two other numbers that could give you a much clearer picture of how well you're aging? In this episode, I talk with physiologist and science communicator Brady Holmer about VO₂ max and heart rate variability, or HRV—two powerful, science-backed metrics that most of us were never taught to track, but absolutely should.  VO₂ max reflects your aerobic capacity and overall cardiovascular fitness, while HRV measures how well your body recovers from stress. The best part? You don’t need to be a marathon runner to improve either of these—and they can be key indicators for longevity, resilience, and quality of life.  Whether you’re new to exercise or already walking and lifting regularly, this episode will give you a better understanding of how to stay strong, mobile, and fit as you age.  As Brady says in our conversation, “Walking is an underrated health hack.” And I couldn’t agree more.  Take a listen—and don’t forget to follow the show so you never miss an episode.  If you’re enjoying Age Better, I’d be so grateful if you left a quick review wherever you listen.   And if there’s a topic or question you’d love for me to cover in a future episode, send me a note at agebetterpodcast@gmail.com. I love hearing from you. Learn more about your ad choices. Visit megaphone.fm/adchoices