India, Sept. 23 -- We often hear that the secret to a long, healthy life lies in watching our weight, keeping cholesterol under control, and maintaining good blood pressure. While these factors are important, they may not be the ultimate key to longevity. Dr John Scharffenberg, a 100-year-old preventive medicine doctor and nutrition professor from California, revealed in an August 25 Instagram post by LongevityXlab the 1 daily habit he believes matters even more, and it might just save your life. (Also read: Physician shares how a 39 year old man swallowed chia seeds and nearly choked; warns 'stop eating' them the wrong way )

Dr John explains in his post, "We need to exercise every day. That's very important. I have outlived my two broth...