Clearly this is old fashioned crap, Having done the Olympian Marathon, an off roader along Wenloch Edge and having done cliff running for training purposes only, while on my hols. I can say that all the serious marathons are off road (PBs not included).
Ok I've gone off on one, hope your hips get better and you do something sensible, a moonwalk, a bike ride, a 10K when you feel better.
People are born with pluses and minuses... I can't play an instrument, speak foreign languages and my eye sight is going. may be you are just not a runner, enjoy the things you can do, before you can't anymore...
I am that sad nack that pulls myself out through the waves on my second hand longboadr hoping to catch a wave... every now and then I get one, I get up in time to steer a bottom turn on the bus I drive these days... but I will still go back for more, because I remember the days when I still could. I remember the sunsets, the dawn patrols, the barrels...
Whatever you do in life, do it wel, enjoy it and stop worrying about the shit you can't do... like make money!!! 