Cardiologist Eric Topol says resistance training, not just exercise, is key to longevity. Capuski/Getty Images hide caption toggle caption Capuski/Getty Images It’s a strange moment for growing old. Longevity is a cultural obsession: Biohackers plunge into ice baths, influencers push peptides, and tech elites pour ungodly sums into chasing immortality. Medical breakthroughs using AI promise to help us predict and prevent disease before it begins. But what actually helps us age well? Cardiologist Eric Topol says the answer begins by rethinking what we’re trying to optimize: not lifespan, or how long we live, but health span, the years free from major age-related diseases like heart disease, cancer or neurodegenerative illness. “The average American health span is 64,” Topol says, referring to when disease is likely to set in. “But lifespan is 79 on average. So you’ve got a big gap of about 15 years where your health span has ended and your lifespan continues.” Topol studies what determines one’s health span and how we can change our experience of old age. At Scripps Research Translational …