It’s a comic book transformation every kid has dreamed of undergoing at one point. Struck by a sudden burst of rage, the gamma rays in frail Dr. Bruce Banner irradiated body trigger his astonishing transformation into The Incredible Hulk. His bones lengthen. His skin turns green (or grey). His shirt rips. And his muscles grow so huge that he makes most Mr. Universe contestants look underfed.
Of course, once readers get a chance to learn how awful the transformation feels for Bruce (having billions of new cells suddenly grow from your body in just a few seconds can’t be a pleasurable experience), they might think twice about switching places with him. Still, this does beg the question – where exactly does all that superhuman muscle mass come from?
How to “Hulk Out”
Regular body builders need to obey a strict exercise regimen and consume a special diet that both fuels their workouts and provides the raw material to build up their muscles over time. Obviously, Banner doesn’t have time to bulk up in this manner, so where does the raw material for his Hulk Outs come from?
According to Hulk’s entry in The Official Handbook of the Marvel Universe #5, the gamma rays added “from some unknown source, over 800 pounds of bone marrow and tissue to his body.” What this “unknown source” is remained unexplained (although many fans took it to be some extra-dimensional source that could provide the raw material for the transformations of other heroes like Giant Man). Amusingly, this dimension might have a lot in common with the “Hammerspace” dimension used by Looney Toons characters (who use it to produce giant mallets and anvils from seemingly nowhere), indicating Hulk’s muscles might share space with some very unusual items.
In X-Men/Fantastic Four #1, Reed Richards of the Fantastic Four offered another theory for where Hulk – and all Marvel superhumans – could get the vast energies needed for their powers. Called, the “Godpower” Theory, the idea, originally proposed by Dr. Rachna Koul, postulated that superhero energies come from one or more intradimensional sources of energy collectively called “Godpower” sources.
However, Hulk writer Jeff Parker offered his own explanation in a tweet, stating, “during transformation he pulls in ambient gamma energy and converts it to mass.” This actually fits in with current Hulk stories that establish the Green Goliath is capable of manipulating gamma energy (i.e. absorbing and expelling it), meaning he could be using some sort of superhuman energy-matter conversion technique.
Of course, the transformation doesn’t simply build a suit of muscles around Banner’s skinny frame. Unlike most heroes, Banner has to literally grow a new body from the inside out every time he transforms. Writers have compared this rapid cell division as having a form of cancer (which makes sense given that Banner got his condition after being exposed to a massive dose of radiation). Unlike cancer patients that develop tumors made of malignant cancer cells, however, Hulk’s “tumors” are his overly healthy superhuman muscles – built from raw energy but grown just like regular muscles, albeit at an insanely rapid rate.
Even after Hulk’s transformation technically “ends,” the cells can still continue forming rapidly if he takes on damage. Wolverine discovered this while battling the Grey Hulk and literally saw the wounds he’d inflicted on the Hulk close up at a rate comparable (and possibly superior) to his own healing factor. Realizing that the Hulk’s mutation was essentially a beneficial form of cancer, Wolverine felt a prolonged fight would be fruitless.
Becoming Banner… Again… And Again
Of course, while growing Hulk muscles is no fun, losing them is arguably worse. Again, the handbooks indicate that when Hulk turns back into Banner, his muscles return to the unknown source that they came from (meaning they could revert to energy and go back to the other dimension or just expel themselves from Bruce’s body into the ambient gamma field). What’s truly disturbing is that, if becoming the Hulk means growing a new, healthy Hulk body, becoming Banner must mean killing off all of those extra cells or allowing them to atrophy.
Strangely, the Hulk actually looks peaceful when he changes back and Banner is usually asleep. This actually makes a lot of sense since – if the process is as painful as it sounds – it would just trigger more stress in the Hulk, which would make him turn back into the Hulk and never let Banner revert. Since Banner does come back periodically, this must mean his body produces a massive amount of gamma-powered painkillers that keeps his pulse rate low and doesn’t trigger another transformation.
Interestingly, while the “ambient gamma radiation” or “unknown source” appears to provide most of the fuel for Hulk’s transformations, even they can’t provide enough energy for Bruce Banner. Some s state that Bruce is incredible hungry after every one of his transformations and needs to consume plenty of protein and fluids as his body readjusts to its normal state. In Ang Lee’s Hulk movie, Banner is shown rapidly eating a plate full of eggs after his second Hulk-Out to show this downside of his superpower.
Hard-Luck Hulk
Sadly, all of this reveals that Hulk really does have the worst luck of all the Marvel superheroes. Captain American and Spider-Man may have gone through some growing pains to acquire their radiation-based muscles, but at least Steve Rogers and Peter Parker got to keep their superhuman physiques after going through the excruciating process just once. Banner, on the other hand, needs to constantly build up his body for every Hulk adventure – and then go through the trouble of losing it and regaining it again.
Even worse, Banner must have a Captain America-size appetite and similar calorie intake requirement – yet while Steve Rogers had the army and the Avengers to provide his meals, Banner is generally flat broke when he reverts to his human form and has to resort to hunting, scavenging, or begging to get the money he needs for food. It’s a rough life – revealing that maybe having the power to “Hulk-Out” really isn’t such a great thing after all.
