"I want to be in the best shape ever"

I have always had to maintain some form of exercise and health considerations due to the Army. I have always struggled with my BF % since I was 40. I am tired of fighting it I want to be in the best shape ever as I turn 60 in 1.5 years. I want to be better than when I was 40. And I want to live on this plain as long as I can so that I can enjoy and keep up with my children and grand-children.