Everyone wants to live a long and healthy life, and there are many things you can do to boost your life expectancy. A heart surgeon has shared his ‘number one tip’ for longevity and it’s something we can all start doing right now. ‘Number one tip’ for living longerSpeaking on TikTok, Dr. Jeremy London said the secret to living longer is doing strength exercises that help you gain muscle. “This is it. Lifting heavy. Gaining muscle,” he explained while training in the gym. As we get older, we lose a significant amount of our muscle mass, so we need to work to keep it. After age 30, you begin to …