How do the bodies of sand boas built for burrowing compare in perceived density to an equally long but slender colubrid?

They often appear heavier or more densely muscled for their length

When comparing the stout, thick-bodied build of a sand boa optimized for burrowing to a snake of comparable length from a family like the colubrids, which are often slender and built for swift movement over surfaces, a visual difference in musculature is noted. Sand boas frequently appear heavier or possess greater muscle density relative to their overall length. This difference is functional: the sand boa's musculature is highly adapted and optimized for the powerful, sustained effort required to push aside and move through dense soil and loose substrate. Conversely, the musculature of faster, surface-dwelling snakes is geared more toward rapid propulsion and aerial pursuit rather than the immense pushing force needed to navigate a subterranean environment.