Vuelta a España

I have been watching the Vuelta a España (tour of Spain) bicycle race. The race is 21 days long and has some massive climbs of Category 1 2 and 3 with some points of over 20% uphill. Most days are averaging 100 miles which the riders are doing in 4 hours at some points going over 50 miles an hour.  Makes my rides of 40 to 50 miles in five or six hours look pretty bad, but then the riders are professionals riding the latest custom built road bikes and are half my age.  I they also do not stop for a break.  Maybe someday I will try to ride the 20 miles to the San Francisco Airport without stopping except for traffic lights just to see how fast I can do it.