As far as Pokémon trainers go, Ash isn't that potent. As far as little kids go, he is superhuman. The 10-year-old isn't only strong for a little boy, he'd be strong for a grown man. As Kotaku previously pointed out, this is because Ash is insanely strong. To recap:
Ash picks up Pignite, who weighs 55.5kg, and doesn't even strain himself.
Ash carries Larvitar, who weighs 72kg, easy as pie.
Recently, Japanese children's show Oha Suta wondered if Ash had Herculean strength and pointed out more examples of why the character "might be superhuman". Might? This kid is.
[Image: the random in my head]
Suddenly, this figure makes perfect sense.
Top image: Pokemon Matome