Akira Toriyama's globally beloved Dragon Ball franchise has followed its protagonist Goku since he was a young boy as he grew up to become a family man and full-on grandfather himself, still staying spry enough to defend the Earth as its mightiest warrior.
And while Goku hasn't lost a step as he enters middle age, Dragon Ball has defied ageist expectations since the franchise's beginnings, with older characters continuing to hold their own against progressively more powerful opponents as the story has leaped decades ahead. This distinction extends beyond the Saiyan leads to its human characters, still perfectly capable of throwing down without missing a beat as they endure the passage of time.
For Saiyan characters, like Goku and Vegeta, Toriyama provided an explanation of how the two characters are able to maintain their relatively youthful appearance, even as they enter their 40s and 50s. At the end of Dragon Ball Z, Vegeta dismissively observes that Saiyans have a genetic trait that allows them to age at a visibly slower rate than humans in order to be able to fight longer at their physical prime. While Vegeta is pushing sixty in Dragon Ball GT, he still continues to become stronger, achieving the Super Saiyan 4 transformation, while both he and Goku unlock new plateaus of combat strength in the Z sequel series Dragon Ball Super.
Dragon Ball introduced human fighters that were the same age, or even years older than Goku, including Tien and Krillin. Initially brought on as Goku's rival before becoming his best friend, Krillin was the same age as Goku at the start of Dragon Ball and is pushing forty by the start of Super. Undeterred, Krillin more than proved himself to still have his edge during Super, sparring with Gohan to a standstill ahead of the Tournament of Power despite having retired from martial arts to focus on fatherhood and his policeman career.
Tien proved even stronger during Super, despite being approximately five years older than Goku and Krillin, lasting even longer than Krillin during the Tournament of Power and facing more opponents from across the Dragon Ball multiverse.
The poster boy for Dragon Ball characters defying age expectations is Master Roshi, a man who rose to become one of the most powerful fighters in the entire series despite being centuries old. With his life extended by drinking the Sacred Water, Roshi was able to best Goku, Krillin, Yamcha and fight Tien to a standstill over the course of the original series. While Roshi took a backseat for much of DBZ, he returned in a big way for the Tournament of Power in Super, outlasting opponents that were significantly stronger than him as he displayed his full combat prowess and experience to great effect.
While Dragon Ball has always featured new generations of fighters fully capable of fighting alongside and against adults -- from Goku and Krillin at the start of Dragon Ball to Gohan, Trunks and Goten during DBZ -- the previous generations still are perfectly able to throw down even as they enter middle age and their twilight years. From the Saiyans' inherent genetic advantage to human martial arts masters' prodigious fitness regimens and mastery of their combat effectiveness, Dragon Ball was never a young fighter's game.
And with Goku and the Z Fighters going strong decades into the story, Dragon Ball is all the proof you need that getting older doesn't mean sitting life out.