Musclelaying is a contemporary sport that is most practiced by teenagers, teenangers, and muscleheads with an attitude. It has been variously described as a nuisance, a bother, subversion, vandalism, and art. Dag Infinite was its first practitioner, and has come under heavy fire at times for popularizing it. He has also been alternatively described as the world's greatest artist.

In musclelaying, a person selects a site upon which a house, mansion, or castle is to be built. They then bury themselves underground, and wait for the structure to be built. Upon the structure's completion, the person then flexes their muscles to the maximum and explodes through the foundation with the intent to surprise its inhabitants. Houses or mansions are preferred, because there is a tendency to flexplode into a dungeon full of dead (and thus uninterested) people if one is underneath a castle.

Some musclelaying enthusiasts have their own spin on things, and may instead be packed into walls by the builders through convincing cosplay of insulating material. They may also bury themselves in groups and coordinate simultaneous flexplosions.

Many attempts to musclelay have ended in tears: most practitioners simply do not have the training to hold their breath for months or years, and even if they do, they often do not have the musclemass to cause a flexplosion, and so sunkenly expire while flexing in vain. However, these poor souls are said to be reborn as Muscle Skeletons — skeletons that are so buff that they can actually compete in bodybuilding contests. Normal skeletons still do not know whether or not to embrace these skeletons as their own. Most Muscle Skeletons say they do not mind having died for a good cause.