What is the biggest predictor of longevity? The answer is more complex than you think
According to a 2018 study in *JAMA* involving over 122,000 patients, higher cardiorespiratory fitness was associated with a significantly lower mortality risk, a finding considered a powerful predictor of lifespan. But pinpointing the single biggest predictor of longevity is not simple, as science reveals a complex interplay of genetic, lifestyle, and social factors that influence how long and how well we live.