You'll be busier in retirement because you'll be living at a different pace. The key is don't stop living. I retired from the Military after 26 years, took a job with state retirement, couldn't stand one day, started a bunch of tests over the next 5-6 months, ended up with severe Arthritis (can you say off the chart numbers) , Fibromyalgia, Plantar Fasciitis, and Carpel Tunnel, along with GWI and empty White Matter in the brain. I had a life event that hit my body that flared and haven't been right since. That was before the Heart Attack in 2017. I was healthy, physically fit, ate healthy, never smoked, 1-3 drinks a month if that and no family history of any of the issues I have. When you get the chance, take the money and run. I ended up quitting Tanking a small state retirement because I couldn't physically keep working to go through the process for disability for the state nor mentally prepared to fight for it at the time. I have a 55 Chevy SB I started to hot rod in the barn and there are days I can't pull a wrench if I can even hold it, even shooting mild recoiling hand guns hurts, and drop more things than I can hold. Tomorrow isn't guaranteed, do those projects now, shoot your guns, go fishing and hunting while you have the health. I get up everyday, some easier than other cause I couldn't get comfortable enough to sleep and keep a healthy state of mind, because your body won't let you forget how you feel, and don't be lured by pain pills of other methods of hiding/masking the pain, face it the same way as you do the cold and misery of pursuing the game animal you want to bag, let the want be stronger than the need and you'll succeed. Good luck and enjoy your time.
