MuscleBob BuffPants is a non-infamous episode. In this episode, SpongeBob orders fake inflatable muscles to impress Sandy.
Why A Few People Think It’s Weak[]
A few people seem not to like this because it "contradicts" what the message of Ripped Pants was telling to the audience
Sandy decides to have SpongeBob try out her workout which is, even for bodybuilder standards, more like a torturous session that skips to the heaviest of the heavy weights than a rigorous but fair workout that'll help build up from easy lifting to putting in effort to lift some of the heavier weights. SpongeBob's body is not suited or equipped for this progressively intense series of warm-ups like push-ups, boxing or running on her giant hamster wheel; but Poseidon/Neptune/Allah forbid he actually went through with the deadly and potentially fatal "Arm Cruncher". So in order to impress Sandy, SpongeBob orders Anchor Arms which should help him give that muscular look. However the Juice Bar is when the downside is revealed:
Anchor Arms are arm shaped balloons that have been inflated with air, this doesn't increase strength so he is still a weakling but avoids detection for now. This is also where Sandy isn't understanding because she didn't listen when SpongeBob said he didn't want to be signed up, but leaves to enter her and him in the competition; which he is too late to stop her from doing so. There is no turning back now...
Let this episode serve as a lesson that there's no substitution for hard work for SpongeBob, and not interested in signing up for an Anchor Toss Competition means exactly that: he's not interested in signing up for a competition for Sandy
Anchor Arms on the other hand might've been meant to be used as a training tool, and SpongeBob didn't understand what their purpose was for until it was too late when he overinflated them to the red Jerk zone; ultimately blowing them up in the end. And if Sandy wanted him to become stronger, she shouldn't put him through a potentially fatal series of warm-up exercises