Science Of Captain America: What’s The Secret Of His Superhuman Strength?

Steve Rogers gets his powers from the Super-Soldier Serum, a fictional chemical concoction developed by Dr. Abraham Erskine that pushes the body’s strength, endurance, reflexes and metabolism to the upper limits of human ability. After the injection, Rogers is also bombarded with Vita-rays in a metal chamber, which stabilize the serum inside his body. The current MCU Captain America, Sam Wilson, never takes the serum.

Even in the league of Marvel superheroes, Captain America stands out as particularly unique. Not because he has a spangly blue costume and wields a shield with stars printed on top (although, that’s also hard to miss), but rather because he doesn’t have inherent ‘superpowers’, per se, like Thor, Wolverine, and Hulk, nor a powerfully weaponized suit of armor like Iron Man, to help him crush his enemies to a pulp. Instead, he’s just a human whose bodily functions have been incredibly enhanced to operate at their maximum capacity.

He’s vulnerable to sharp-edged weapons, regular bullets, and even the brute force of a punch (although that punch has to be pretty darn hard), just like any other “normal” human. This is probably one of the reasons why Captain America resonates with people, as people find him to be someone to whom they can relate.

But how are his bodily functions so enhanced? What’s the secret behind his extra agility, extra strength… and basically every other human ability with the prefix ‘extra’ or ‘super’ attached to it?

Super-Soldier Serum

The main secret behind Cap’s superhuman strength and endurance is the Super-soldier serum, which is a fictional concoction that has been used in the Marvel universe from time to time. It’s basically a homogeneous combination of ‘certain chemicals’ (that have not been named, obviously!) in the form of a liquid, exclusively prepared by a scientist named Abraham Erskine, code-named “Professor Reinstein”.

Once administered to a human body through a series of treatments involving both ingestion and injection, the body transforms itself both mentally and physically to operate at the peak of human performance, and perhaps even beyond that.

The super-soldier serum was formulated to create incredibly advanced super-soldiers during the time of the second World War to help lead the Allied Forces to a swift victory. Steve Rogers, aka Captain America, was selected as the first test subject for this formula as a part of “Operation Rebirth” due to his unparalleled courage and staunch patriotism for the country.

Vita-Rays

Super-soldier serum certainly has the potential to exponentially increase human mental and physical strength, but it requires an altogether different system to stabilize it inside a human body at an accelerated pace. After having been administered the serum, Cap was put in a metallic chamber and bombarded with special rays that could do the trick. Referred to as Vita-rays (another ‘Marvel-only’ thing), these rays sped up the effects of the serum and stabilized them within Cap’s body.

Talking about the miraculous effects of these rays is one thing, but being exposed to them at 100% of their capacity in a metallic chamber is another. The transformation was a painful procedure, to be sure, but its results were textbook perfect!

Here’s a short clip of the transformation of Steve Rogers into Captain America. Take a look:

Steve Rogers Before And After The Serum

Before Erskine’s serum went to work, Steve Rogers was about the least likely super-soldier candidate you could picture. In both the comics and the films, he is a scrawny kid from Brooklyn standing roughly 5 feet 4 inches (163 cm) and weighing somewhere around 90 pounds (41 kg). He is stamped 4F (unfit for military service) at the recruitment office again and again, and the character is written with a long list of ailments to match, including asthma, scoliosis, a heart arrhythmia, partial deafness, stomach ulcers and pernicious anemia.

Then comes the injection and the Vita-ray bath. When Rogers steps out of Erskine’s chamber, he has been rebuilt into a completely different specimen, standing about 6 feet 2 inches (188 cm) and packed with muscle. Nothing was bolted on from the outside; the serum simply pushed every cell he already had to the ceiling of what a human body can be. That dramatic skinny-to-strapping jump is exactly why “Captain America before and after” is one of the most searched moments of his whole origin story.

What Are Captain America’s Powers?

Here is the part that trips people up: Captain America does not really have “superpowers” in the way Thor or the Hulk do. What the serum and Vita-rays give him is a body dialed up to the absolute peak of human capability, and then nudged a single step past it. In Marvel’s comics his strength sits at the very top of the human range and a step beyond: the official power charts have him lifting around 800 pounds (about 360 kg) over his head, a load no real-world lifter could press. He has been clocked running at around 30 miles (48 km) per hour and covering a mile in under a minute.

His stamina is enhanced just as much, to canonically superhuman levels: his body resists the fatigue that would drop an ordinary person, so he can keep going far longer before he tires. Layer on peak-human agility, reflexes and durability, an immune system that shrugs off most diseases and poisons, and a healing rate quicker than a normal human’s (though nowhere near Wolverine’s). The serum also keeps his cells from aging normally, which is the in-universe reason a man born in the 1920s can still throw a punch in the present day after decades frozen in Arctic ice.

Just as important, and easy to overlook, is what happens above the neck. Erskine’s formula sharpens the mind as much as the body, handing Rogers heightened tactical awareness and split-second judgment that make him one of the finest field commanders in the Marvel universe. The near-indestructible shield he throws, forged from a rare vibranium alloy, is equipment rather than a power, but in his hands it turns all that enhanced strength and reflex into his signature weapon.

Could There Be A Captain America In Real Life?

All this talk about Captain America’s super agility, super strength and super endurance is all well and good, but is it possible to replicate such a mechanism in our world to create real-life super-soldiers?

As of now, we haven’t figured out a way to concoct a super-soldier serum, but looking at the effects that the serum produced on Cap’s mind and body, scientists have identified a number of genes that could be tapped to recreate such results in normal humans. Specific genes, such as those involved in improving the oxygen-carrying capacity of blood or increasing muscle mass, can be hyper-activated using certain techniques.

Sebastian Alvarado, who was a postdoctoral research fellow in biology at Stanford University when he first wrote about this and is now an assistant professor of biology at Queens College, CUNY, has argued that genome-editing tools available today (zinc finger nucleases and CRISPR/Cas9, joined more recently by the more precise base editing and prime editing techniques developed by David Liu’s lab) can hyper-activate or silence specific genes to nudge the human body toward the best possible (and practical) physical health. In principle, the same toolkit could make you more strategic, sharpen your problem-solving, supercharge your reflexes and make you faster.

A Need For Real Vita-rays

We do have, at present, techniques that can alter your genetic code and bestow you with certain superhuman features; what we still need is the Vita-rays, or the ‘scientifically and practically plausible’ version of Vita-rays, which could stabilize such genetic alterations in the human body.

Of course, such tests have not been carried out on humans in real life. The biological complexities and ethical considerations are yet to be worked out to pull this fantastic feat out of the Marvel universe and apply it in real life.

As far as making a real-life Captain Americas is concerned, the future does look bright. However, enhanced physical and mental muscles are not the only things that make one a superhero; the traits of one’s character are also key elements, and those, my friend, can never be altered by any super serum!