In that same piece, the last note (played by non-explosive instruments) is marked with fff, and then goes into a crescendo from there. As Malacandra says, we brass players did indeed take this as a challenge.
Traditionally you divide the orchestra into 4 groups of instruments, but I really like Chronos’ approach: the explosive and non-explosive!
My favourite (as a trombone player) is tutta forza, which I usually mentally translate as “let 'er rip!”
This brings back memories of playing Stars and Stripes Forever in marching band. In the last pass through the last movement, we trombones with the counter-melody would try to out-blast the trumpets with the melody. The director wasn’t especially pleased about the competition, but we trombonists weren’t going to let the trumpets get away with all the glory.
What is it about trombones (and tubas, too) that gives their players too much attitude? (I always imagined Melkor was a trombonist. 
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Simply put, low brass kicks ass. And I definitely agree about Melkor :).
Many people know of the recording of a live performance of Verdi’s Requiem conducted by Arturo Toscanini. Non-musicians may be interested to know that tutta forza is notated in the “Tuba mirum” section of the “Dies Irae”. At that point in the recording, you can clearly hear Toscanini shouting “Louder, louder” to the brass.