The manga and anime series One-Punch Man centers around Saitama, a hero capable of eliminating any opponent with a single punch.
While this premise provides an interesting take on boredom and the consequences of reaching an unbeatable status, it also raises an important question—how did Saitama achieve such immense strength in the first place?
The growth limitation theory might hold the answer to Saitama’s strength (Photo: One Punch Man/Madhouse)Throughout the series, this question has intrigued many characters. The first to ask was Saitama’s disciple, Genos, who received an incredibly straightforward answer: Saitama claims he trained daily by doing 100 push-ups, 100 sit-ups, 100 squats, and running 10 kilometers for over a year.
Both Genos and a scientist from the House of Evolution who overhears the conversation find this explanation absurd, as the routine itself is not particularly demanding. Saitama, however, remains adamant that this was the key to his power, even attributing his hair loss to the intense regimen.
Despite his insistence, Genos becomes convinced that Saitama himself is unaware of the true source of his strength.
Breaking the Growth Limitation
Superhuman abilities in One-Punch Man do seem to stem from extreme physical conditioning in some cases. Characters like Superalloy Blackluster and Puri Puri Prisoner have gained immense strength through training, with Blackluster beginning his journey as a bodybuilder.
However, unlike them, Saitama does not exhibit an overwhelmingly muscular physique, making it difficult to believe that his physical routine alone could have produced such results. Even if his strength could be attributed to this training, it would not explain his other extraordinary abilities, such as enduring fireballs or remaining entirely unscathed after relentless enemy attacks.
Some characters, including the scientist from the House of Evolution and the secret mastermind behind the Monster Association, Psychos, have attempted to rationalize Saitama’s limitless growth through the “growth limitation” theory.
According to this idea, both humans and monsters possess a natural cap on their abilities, preventing them from growing beyond a certain threshold. However, in rare cases, an individual may manage to break through this limit, allowing for boundless development.
Psychos theorized that near-death experiences were the most effective means of surpassing this barrier and conducted experiments on both Monster King Orochi and later Garou. Interestingly, Saitama himself has mentioned that his training often made him feel as if he was on the verge of death, suggesting that he may have unknowingly surpassed his own limits through sheer perseverance.
The Possibility of Divine Intervention
Another intriguing perspective on Saitama’s strength links his abilities to a divine entity. One-Punch Man has introduced the idea that some superpowers originate from a higher being. A prime example is Homeless Emperor, a lieutenant in the Monster Association, who appears to be an ordinary human but wields immense energy projection abilities.
He claims that these powers were bestowed upon him by God during a moment of despair, after which he embraced a mission to eradicate humanity. This concept of divine intervention is reinforced by Vaccine Man, the first villain introduced in the series, who also claims to have received his abilities from the same entity, viewing humans as a destructive force.
The idea gains further credibility when considering an encounter between Saitama, Flashy Flash, and the monster Oculette, who came across a mysterious cube within the Monster Association’s headquarters. Upon touching it, they briefly communicated with the same god-like being that granted Homeless Emperor his power.
This entity offered them a chance to prove their worth—either by receiving greater strength or having their existing abilities stripped away. None of them accepted the offer before Blast, the top-ranked hero, arrived and intervened.
When you’ve got the skills, you don’t need the muscles (Photo: One Punch Man/Madhouse)Upon seeing Blast, the entity immediately recognized him, while Blast revealed that he had been collecting these cubes and appeared to be familiar with this god-like figure. A previous flashback to Tatsumaki’s childhood also depicted Blast with one of these cubes, further deepening the mystery surrounding his connection to this being.
This theory suggests that Saitama may have unknowingly gained his strength either through direct contact with one of these cubes or as an unintended recipient of divine power.
Unlike Homeless Emperor and Vaccine Man, who share an anti-human ideology seemingly aligned with God’s purpose, Saitama’s accidental acquisition of such power might explain why the entity does not acknowledge him the way it does with Blast.
Another possibility is that God does not discriminate when granting power, offering it to anyone who meets certain criteria without considering their moral stance. However, if this were the case, it raises an important question—why does Saitama have no memory of such an event?
Blast’s actions imply that this god-like being poses a tremendous threat and must be avoided, making it unlikely that it would willingly grant abilities to someone actively working against its objectives. If Saitama is unknowingly drawing power from this source, there remains the risk that it could be taken away at any moment.
An alternative theory suggests that this entity is not the only one of its kind, and that another being, acting in opposition to it, may have empowered Saitama instead. Since Blast’s origins and abilities remain equally mysterious, some speculate that he serves as an emissary for this opposing force, working to prevent divine interference by collecting the cubes.
If true, this could mean that Blast and Saitama share the same power source, potentially extending to Tatsumaki and Fubuki as well. Despite the numerous theories surrounding Saitama’s extraordinary abilities, no definitive answer has been provided within the series.
Given One-Punch Man’s unconventional approach to storytelling, it remains uncertain whether this mystery will ever be fully addressed. A traditional superhero story would likely incorporate a major revelation about the protagonist’s origins as a key plot point, and the series may eventually follow that path.
However, considering One-Punch Man’s tendency to defy expectations, it is equally possible that Saitama’s strength will remain an unexplained phenomenon, reinforcing the idea that the series is more about the journey than the answers.