Sit-Ups, Crunches, Planks, Knee-Ups: The Evolution of Core Fitness Testing

How to Do a Correct Sit-Up, Plus Benefits and Variations

7 Exercises To Build Up Your Core if You Hate Sit-Ups

Sit-ups and Back Pain

Forget sit-ups — you only need a pair of dumbbells and 7 exercises to sculpt your abs

7 Weeks to 300 Sit-Ups: Strengthen and Sculpt Your Abs, Back, Core and Obliques by Training to Do 300 Consecutive Sit-Ups: Stewart, Brett: 9781612430492: : Books

Evaluation of Possible Anthropometric Advantage in Sit-Up Test – The Sport Journal

Best and Worst Core Exercises for Athletes - Youth Sports Trainer

Can I build muscle just by doing push-ups and deadlifts? - Quora

Pavel Tsatsouline's Guide to Pushups, Sit-Ups, and Squats

Forget Russian twists — this is one of the best ab workouts at home without equipment

4 Ways to Do Sit Ups - wikiHow

Celebrity Trainer: The 3 Best Abs Exercises for Women

Say Goodbye to Sit-Ups: 7 Ab Exercises That Are Even Better for Your Core

20 Best Core Workouts For Women - Core Exercises For Stronger Abs