The right attitude is everything. Don't be the guy who thinks that he can skate just because you're older and a veteran. Police academies are para military, but I doubt they are nearly as hard as military training. That said, if you become a problem child, the instructors will pick on you until you fix yourself or you're out. Physically, it shouldn't be a challenge for you, like it will be for younger fat kids that don't have your background. Academics can be tough. Expect a 70% or higher passing score on all tests and only a few tests that you can fail before getting booted. Devote majority of your time to studying the material, streets, laws, etc. Academy is just the first step, and in my opinion, the easy part. You can blend in with the class and make it through. Once you get out on the street, expect stuff that contradicts some of your academy experiences and training officers that are much younger than you, but single handedly control your carreer. And their focus is 100% on you.