12 Week Mass Building Workout!

By: Nathan Underhill

I am now 4 weeks into a 12-week mass building phase, and I am very pleased with the results so far. I am using mostly compound movements with the reps between 6 and 10 on all exercises. Each body part is trained 1 time per week on its own day, for a total of 6 workouts per week with Sunday off. On every exercise use as much weight as you can, while still maintaining good form.

Here are my results after the first 4 weeks.

Arms + 3/8 inch
Chest + 1/2 inch
Quads + 1/2 inch
calves + 1/4 inch
Weight + 8 lbs

Chest (11 sets)
Barbell bench press 4 sets
Incline barbell bench press 3 sets
Decline barbell bench press 2 sets
Incline dumbbell flyes 2 sets

Back (12 + sets)
Chins do as many sets until you reach 30 reps
Barbell rows 4 sets
close grip chins 3 sets
Deadlifts 4-5 sets

Legs (13-16 sets)
Squats 4-6 sets 6-12 reps
Leg curls 3 sets
Leg ext 2-3 sets
Standing calves 4 sets

Shoulders (12-14 sets)
Barbell shoulder press 4 sets
Arnold presses 4 sets
seated laterals 2-3 sets
Bent over laterals 2-3 sets

Biceps (8 sets)
Barbell curl 3 sets
Preacher curl 3 sets
Seated dumbbell curl 2 sets

Triceps (10-12 sets)
Close-grip presses 4 sets
Overhead tri ext 4 sets
Reverse pressdown 2-4 sets

In order to keep from overtraining when doing this routine and to put on maximum size it is important to eat a lot. If you are not seeing very good gains the one thing to always remember is to eat more.

Supplements I am taking:
-Protein powder
-Weight gainer

-Eat every 2-3 hours
-Get as much sleep as possible, 9-10 hours
-Try to get at least 1g of protein per lb. of bodyweight

Bulking phase weeks 4-8

Here it is at the end of the 2nd month of my bulking phase. These 4 weeks I still stuck with the same routine as the first 4 weeks, heavy weights with 6-10 reps per set. My results these 6 weeks were limited because of sickness. I was sick 2 times this month and that resulted in quite a bit of time off. And on top of that I had to leave town for 4 days to go to a wedding, so part of this month was somewhat of a waste. Also because of my throat I was unable to eat very much so my calorie consumption was lower than it should have been. All that said, here are my results for this month.

Gains: weeks 4-8 Total gains after 8 weeks
Arms- + 1/8 Arms + 1/2 inch
Chest- + 1/4 Chest + 3/4 inch
Quads- + 1/4 Quads + 3/4 inch
Calves- + 1/8 Calves + 3/8 inch
weight- + 5 lbs Weight + 12 lbs.

Bulking phase weeks 8-12

This month I decided to switch things up a bit. I changed my arm routine to try to shock my arms a little, and I lowered the reps on my squats to get a little break from the higher reps. I Did a month of heavy squats doing 8 reps down to 1 or 2. It helped the weight to go up and shocked some new growth into my thighs. For triceps I did incline close grip presses instead of flat and it really sparked some growth. Here is the routine.


For biceps I have been using a routine similar to the one Larry Scott used, Doing the entire bicep workout on the preacher bench. I also raised the reps I used for arms to 8-12. Using this routine I have had some of the best arm growth I have ever had, and my biceps look fuller.

What surprised me was that it also helped improve my biceps peak. If your having trouble with your biceps, give this a try for a month. Remember, intensity is the key. Force yourself to do 1 more rep!

Barbell Preacher curl (don’t use EZ curl bar) 3 sets
Reverse preacher curl (EZ curl bar) 3 sets
1 arm dumbbell preacher curl 2-3 sets


Incline close-grip bench press 4 sets
Seated overhead tri ext 4 sets
reverse overhead tri ext 4 sets (awkward, but effective)


Squats 5 sets 8 reps or less increase weight on each set
Hack squats 3 sets 8 or less feet close together and pointing out
Leg curls 3 sets 8, 6, 4


Barbell bench press 3 sets
Incline barbell bench press 3 sets
Decline barbell bench press 3 sets
Incline dumbbell flyes 2 sets


Chins 30 reps total
Barbell rows 4 sets (try doing some with palms facing away)
Deadlifts 4 sets


Barbell shoulder press 3 sets
Arnold presses 3 sets
Upright rows 3 sets
seated laterals 2-3 sets
Bent over laterals 2-3 sets

Here are my final results after 12 weeks:

Arms + 3/4 inch
Chest + 1 1/4 inch
Legs + 1 inch
Calves + 1/2 inch
Weight + 16 lbs.

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