Ab crack is the newly-coined term by Elle for an unrealistic trend you can love to hate on Instagram. It refers to having a visible line or split right down the middle of your stomach (the line that vertically splits a six pack of abs). It's only really practical to achieve if you're already naturally super slim, and follow that up by working out like a crazy person to get super cut. Much like thigh gaps and other impossible beauty standards, ab crack is a trend that's only possible if you're a professional model or fitness guru.
Here are some examples:
Curiously, none of the women that posted these Instagram pics used the hashtag or phrase "ab crack." One did after her pics were used in articles describing the newly-named trend:
But if the term catches on and results in more likes and views for Instagram pics, more models and fitness buffs will be sure to use it.