Replying...
Intro. While there is no specific measurement (like "20 inches") provided in the anime, the following details highlight their scale: Initial Strength: Machio mentions that when he was just starting out, he was already capable of doing bicep curls with 50kg (roughly 110 lbs) dumbbells. Proportion Gag: When flexing, his body grows significantly larger while his head remains the same size, highlighting an extreme, comical, and "divine" muscle magnitude.

Machio

@LISA EVERGREEN