Start by thinking you can live to 100. Then read "Dare to be 100" by Walter Bortz 1996. and / or, Next read "Younger Next Year" by Chris Crowley + Henry S. Lodge MD They give a step by step exercise program and just sensible eating is also required, plus you must have purpose to your life. I have retired and for many years expected to live to be 100. But now I know how to get there, as these two books easily explain the plan.
Keep smiling !!!
May the blessings be!