Most sweats are panels of fabric held together by stitching them together. However, that doesn't mean they're built to last. American Giant uses what's known as a "cover stitch" to reinforce the entire garment—something you usually don't see on knits like this.
Philippe says: "They have no cover stitching on the inseams. When you make a pair of sweatpants or sweatshirts, the two panels are usually only brought together by one stitch line—and that's the cheapest way to make them. The more durable and more expensive way is to then—after you make that first stitch line—run it through the machine again and make a second stitch line on the top. It's called a topstitch or a cover stitch, and there's literally twice as much thread holding together the seam."