bruh when did I say "effects of ALL superpowers"? I'm just arguing for saitama's ability to ignore effects that influence or control biological functions? Biological functions, as in, how the body works. JUST shredding muscle fibers? Bruh read up on how too much exercise does to your body and you'll see how absurd what saitama managed. Dont forget the constant monster fights, the lack of proper calorie intake and uncaring for nutrients, no way to heal the injuries, stacking damages, and self inflicted torture through winter and summer. Like I mentioned before, basically an exponentially increasing state of inoperability.
Like yeah if you cut off his hand, its gone. But if you break every bone in his arm, inject it with paralyptic chemicals, and sever the muscle and tendons, I rekon saitama would be able to operate it like normal with enough willpower.