Spit in a tube, mail it off, get back a number that says your cells are "7 years younger" than your birth certificate. Epigenetic age testing has become the trendy way to measure how you're actually aging, and the marketing makes it sound like the whole answer. But what does it actually mean for you? Epigenetic clocks look at chemical tags that attach to your DNA at specific locations that shift in predictable patterns as you age. Run enough of these tags through an algorithm

Everyone's chasing a single number now. $200 DNA kits, $700 blood panels, $10,000 clinic programs, all promising to hand you your "true" biological age. Unfortunately, a lot of them can't even agree with each other. Different "clocks" measure different things. GrimAge predicts mortality risk, DunedinPACE measures your pace of aging, PhenoAge runs off blood biomarkers. There's no mandated reference range, no standardized method. Saliva and blood samples from the same person, r

Try Googling "functional fitness assessment older adults." What you'll get back is a stack of academic papers. Systematic reviews. Sensor-based gait analysis studies. Nothing that actually tells you, in plain language, what this is or why it matters. Why? Because although there is tons of well-validated research on the topic, most if it has just never made it out of the journals and into anything a person can actually use. So here's the plain-language version, specifically wh

Everyone's watch has an opinion about your VO2 max now. Garmin, WHOOP, Oura, Apple Watch — pull up the app and there it is, a number supposedly telling you how fit you are. Turns out that number is mostly a guess. Your watch doesn't, and physically cannot, measure VO2 max. Instead, it estimates it using your heart rate and your pace. A real VO2 max test measures the actual gas you're breathing in and out while you work at your cardiometabolic limit. Your watch has none of tha