Jogging isn't good for the joints though!   Prefer brisk walking myself  

 and don't do mud  

.  I watch people running up and down places like Helvellyn and they don't see the scenery which is partly why I go out and about.  
I've never conformed  
 
  
 so never feel pigeon-holed.  We read.  Walk.  Garden.  We used to cycle ......... but I don't see much of the scenery as roads are so FULL of potholes [is that contracdictory].  
How far would you go?  Is trail running like orienteering?  I know that they do mud swimming in Wales but that's too wet and cold for me to even consider  

As for being 'old' - age is a number and I can't find any organisation that actually knows what 'old' or 'elderly' means  
 
  