saltfish

Good question!

From experience you need to develop a workout program that will include a power-lifitng day for mass as well as a definition day for muscular endurance.

Your power day will include chest day that allows for very high weight and low reps, 5 sets / 5 reps or 3 sets / 3 reps. For the chest, I would recommend bench, two or three good tricep exercises as well as an overhead dumbell press.

Your definition day will include 3 sets of 10-15 reps followed by a 4th set of 20-25 reps. Make sure to vary the exercises so that various parts of the muscle group can get their specific attention. This day can be a little more difficult in terms of guaging the weight that you would need to use. With some practice, you can determine the amount of weight needed in order to barely be able to finish the last set.

Overall, remember that in order to see big gains you will need to push 100% and never give up.

Afterthought: Remember that your chest and arms do not like to be worked every day. It would be advantageous to work a power day followed by a day off, then a endurance day, then a day off. Couple that with proper nutrition, cardio and ample, daily stretching and you will notice a difference in only a few weeks.