Shoulder endurance

[gramm]

Punchout drills: a timed interval on a heavybag where you throw a continuous 1-2 combination as fast as possible. Start with 30 seconds, rest 30 seconds, 30 second punchout, rest, etc for 1-4 three minute rounds. Eventually you can rest less, increase the length of the interval, or # of rounds.

Polish Boxing: with light db's or resistance tubing. Same as above but without hitting a heavybag and the rest becomes a slow and deliberate 1-2 combination that focuses on form.

Shoulder circuit: 30 seconds each with a 2lb or heavier db (sometimes lighter is better), be fast and but deliberate.
overhead punching
straight punches
bent over lateral raises
lateral raises
uppercuts
"static" hold in front of your body (make lil circles to make it harder)

I Got that same workout from A title boxing training dvd, and its great. I do three rounds of it after my daily run, and punch speed is has went up like crazy.