Got to admit I am over 70. My concentration- Think putting on 500 to 600 miles a day and 10,000 miles is fair concentration. This was last summer Fl to Colorado. Tired of winter, so I am packing now for a early run to Texas and Mexico before heading north to Alaska. I think the secret is to just do it that which gives you pleasure. I had been Solo sailing-trans-Atlantics on my 35ft sloop. . Last year I back packed across Europe from London to Turkey for 3 months. I got pneumonia from all the smoking and fowl air in the big cities, so now I am only going to the open country. I am playing with putting a hack on to carry more gear and fuel. Figure it out if you do 600 miles a day how many gas stops are necessary with a 4 gallon tank. . I ran out of gas in Missouri because the two stations across Missouri RT 64 to Colorado never opened on a Saturday. In July it was as hot as blazes and a drought. I take offense of the dude mocking the Over the Hill 70 Riders referring to back pain etc etc . Hey my my 23 year old girl friend complains just as much with just headaches. See you on the road-toad.