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

Core strength testing has come a long way from the straight-legged, twisting sit-ups used before World War II.

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

Forget sit-ups — this 3-move ab workout chisels concrete core

The Best Sit-Up Variations for a Strong Core

The Best Types of Sit Ups - SportsRec

The Truth about Whether You Should Crunch or Plank Your Way to a

Intentional breathing in a core training programme - Sportsmith

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

The Major Differences Between Sit-Ups and Crunches

Here's What A Good Core Workout Really Looks Like, thePTDC

Forget sit-ups — 10 best crunches and variations to…

How To Do Sprinter Sit-Up

4 Benefits Of Sit-Ups + Why Your Next Workout Routine Needs Them

How to Do Sit-Ups: Tips, Technique, Benefits, and More

How To Do Sit-ups - Benefits, Muscles Worked

Are Sit-Ups Bad for You? Sit-Ups vs Crunches vs Planks