When I went on my Honeymoon during the spring of 2017 I packed a book with me called Thinner This Year by Chris Crawley and Jennifer Sacheck. Although reading a book about eating healthy and working out while vacationing at an all-inclusive resort with unlimited food and drinks might sound contradictory, this book gave me a nice "shot in my arm" that has helped me to continue working out into my mid-30's.
There was a theme that resonated time and time again in this book that said "Exercise, six days a week, for the rest of your life." While I have been working out and lifting weight consistently since 2005, it was great to see this put so bluntly in writing.
Another candid line that can be found in the book that has really resonated with me is the following: "Movement, all the time, is the single, great key to keeping your body from going completely to hell after age thirty or forty or fifty. Which is it absolutely guaranteed to do, in idleness." I don't know about you, but the idea of my body turning into mush after the age of forty is pretty frightening and alone is one factor that gets me motivated to go the gym day after day.