As I originally stated most reasonable cal's with reasonable bullets will take elk when properly placed. The vast majority of deer & elk I have taken over the years has been under 200yds. Not to say longer shoots can present them selves. As some one who is 75 , still in great shape & been hunting since I was old sough to do so I appreciate an accurate rifle. When it comes to rifles open sights have saved my hunt a couple times in past years. Scopes can be damaged from falls in an instant.I see back up open sights as being prepared. . Have you ever been in the back country slipped & fell & bent your scope eye piece. I have . In my opinion wisdom says back up open sights are mandatory.
As far as staying in shape my every day activities seem to take care of that at the 7630 ' I live at. My point is make sure your rifle is sighted in with a proper bullet need for the intended game. That is "EASY". The hard part as I see it is being physically prepared. The mind is willing but the budy's lust for pizza, donuts , cake, ice cream , cheese, pepperoni & such can be over whelming for some. A strong mind set & a willingness to suffer to obtain any goal shows the charter of the individual. Am I perfect. Absolutely not. It's just that I have the good fortune to live at a high elevation to start with & a looooong way from the grocery store.