Chappedstick - There’s a thread stuck to the top of the Newbie Forum that all new guys are encouraged to read. It’s called Important Newbie Threads/Info. In it is a list of other threads that contain a wealth of information and which answer almost every newbie question. One, appropriately titled, is The most often asked and annoying questions! You’ll find the answer to this question there.
I’ll also point you to the top right of every page where the search button is located. If you use "masturbation gains" as the search term you’ll get over 100 threads in which those two words appear. Look thought the titles and you’ll find almost every other thread about this subject. If you search for "masturbation PE" you’ll find all the others. There must be a thousand by now. :)
The short answer, and don’t let me telling you prevent you from reading the newbie material, is that there is no effect on gains by masturbating before, during or after your PE exercises. Masturbating before your workout may make it difficult to get an erection and decrease your performance during the exercises. Masturbating after may cause your penis to shrink a bit (perfectly normal behavior) which some guys think means they didn’t have a good workout, but that’s not true.
Jerk away!