Giorgio Chiellini struck the only goal of the game midway through the first-half.
It was the Bianconeri's first clean sheet after 19 games.
"No team can play without decent fitness levels," explained the Juve Coach.
"Now we can train and it shows, as it's no coincidence we didn't collapse in the second half.
"The many injuries were not decisive, but they did force us to always field the same men, even when they were in no condition to do so."