Here is a GREAT column that highlights the amount of gamesmanship and coverage that would go into morning workouts 100 years ago.
http://kdl.kyvl.org/cgi/t/text/pagev...15120801%3A3.2
Obviously -- that was at a time in history when things were much more favorable to the bettor -- and you could make a large amount of money much, much, much, much more easily by successfully putting over the horse in the morning.