To increase muscle mass it's important to shock the muscles as much as you possibly can, training with the same old routine will eventually lead to plateaus that are hard to break so it's important to constantly change up the workout routine as much as possible.
Here are a few exercises that were performed by some of the greatest bodybuilders of all time which is why they have always stood out and will continue to be legends as long as the sport of bodybuilding exists.
The forearm roller
Forearms are often neglected and while they do get worked when performing other exercises such as deadlifts, t-bar rows, and barbell curls, the workout the forearms get are only secondary.
The forearm roller directly works the forearms, you can make your own roller for just a few bucks, all you need is an old broomstick and some rope.
Attach a 10 or 15 pound plate to one end of the rope and the other to a 25 to 30 inch broomstick and roll it up and then roll it down as you get used to this exercise you can gradually add more weight and make those forearms massive.
This was one exercise Arnold performed regularly and it was most likely why he had a massive chest and incredibly wide rib cage, this exercise does more than widen the rib cage it also exercises the pectoral muscles, lats, back and to some degree the tricep muscles.
There is a lot of debate on when to perform this exercise, on back or chest day, probably because it targets both.
Arnold used to superset back and chest during the same workout so the pullovers were part of his supersets, I personally perform this exercise on chest day because working out back leaves me depleted.
Some like to rest their shoulders on the edge of a bench letting their torso hang making their legs the main support when performing this exercise, others choose to lie down on the whole bench for better support.
Lying lateral raises
Shoulders are an important body part, they create the illusion of width, if you want to become massive it will be hard to keep the illusion of the V-taper with small shoulders, when training shoulders it is important to hit them at all angles and one exercise that is important that many neglect is lying lateral raises.
This was a favorite of Serge Nubret who is known for performing this exercise regularly, it was also one of Arnold’s favorites, while most bodybuilders commonly perform front and side lateral raises, hitting the delts from all angles will stimulate more growth, for many the delt muscles are difficult to make grow.
Performing side lateral raises can be a little tricky and may take a while to get used to them but once you have mastered this exercise you can expect incredible shoulder growth
To perform the exercise you lie sideways on a bench and with light to moderate weight bring your arm all the way up to where it points to the ceiling and then lowering it down “keeping constant tension”, this exercises emphasizes a lot on working the middle delts.
One arm hanging concentration curls
Arnold had some of the best biceps in the industry and he knew how to work them out, one of the exercises he used to perform was hanging dumbbell curls.
To perform the exercise you lean over “bending at the waist” and making sure your upper arm is straight, you then curl the dumbbell up towards the shoulder, make sure you squeeze on the contraction and bring back down, using light to moderate weight can give you a great pump, this exercise is essential for developing a big peak in the biceps.
Cross-chest dumbbell extension
This is a variation of the dumbbell skull crusher this difference being instead of coming down to the side of your head towards the ear you hold the dumbbell and bring it down to the opposite side of your chest, this exercise is a good finisher after a tricep workout as it really helps get the blood flowing into the triceps
This is one exercise performed by the famous Tom Platz who had some of the best legs in the bodybuilding world, sissy squats can be performed on a hack squat machine and instead of going straight down to actually bend forward, letting the knees bend down and roll forward, you will almost never see anyone performing this exercise and for me personally it puts a lot of stress on the knees, sissy squats can also be performed without weights, you can perform these by grabbing on to a door handle leaning forward in a similar motion .
Some of these exercises will have to practice several times before you manage to perfect your form so its best to start out with light weight until you have mastered the movements and then you can begin increasing the weight.