How much physical energy does it ACTUALLY cost you to worry about the future? Dr Martin Picard's research argues stress isn't just a mental weight - it's an expensive biological tax on your cells. In his lab, when human cells were exposed to stress hormones, the energy cost of just staying alive inside those cells shot up by 60% (He’s also the scientist whose team literally sliced a human brain into 703 cubes just to map how energy moves through it 🤯) You have a stressful morning, a difficult conversation, or a few anxious thoughts you can't shake, and by 2pm you feel completely drained. Your mind is tired, but your cells are genuinely exhausted. Dr Martin Picard is a Professor of Behavioural Medicine at Columbia University and I sat down with him to understand how our emotions and lived experiences physically change the mitochondria inside us - the tiny structures responsible for producing all the energy we rely on. My energy has always felt a bit like roulette. Some days I wake up feeling incredible, other days I feel like I've done the exact same things but I've got nothing in the tank. Martin completely reframed how I look at this. Energy isn't just a biological default; it's one of the most important scientific questions of our lives. We discussed things like: - Why you can do everything “right” (sleep, diet, exercise) and still wake up completely exhausted. - The physical tax of stress and what a single anxious morning does to your cells. - Why mitochondria are the missing link behind burnout, depression, and chronic fatigue. - What actually dictates your cellular energy day-to-day. - The truth about whether fasting, meditation, deep purpose and relationships can rewrite your biology. This is a conversation about understanding what your body is constantly responding to where your energy is actually going and why so many of us feel tired in ways that more sleep or more food don't always solve. If you feel flat, anxious, or exhausted and can't explain why - this one's for you. Watch our full conversation now on YouTube, Spotify or Apple Podcasts. Search "The Diary Of A CEO Dr Martin Picard". #burnout #greyhair #fatigue #scientist #scientist - @steven