Ten Worst Exercise Mistakes 4 By Dr. Nick Campos On April 10, 2010 · Add Comment · In Uncategorized Abs are endurance muscles, not muscles of mass like gluts or pecs—adding weight for resistance can lead to injury. Think reps not plates: Wrong! Adding weight for resistance during crunches can lead to injury. Right! As endurance muscles, reps will get you farther than weight when it comes to abs. Burn ’em baby! Next