Leigh Erin Connealy, M.D. on Instagram: "Today, there’s an intense focus on longevity—slowing aging, preventing disease, and preserving function for as long as possible. We’re sold endless supplements, potions, and protocols promising to keep our cells young. Some are useful, many are not. But one of the most overlooked drivers of longevity isn’t something you can buy—it’s how the body experiences energy, stress, and engagement with life. Youthful physiology is defined by high metabolic rate, fl