Its always cool in some form to have muscular areas around the body like washboard abs, toned arms, big chest, a back the size of Texas and legs that looked like they're carved from granite but at most having rippling muscles aren't always going to save you. When it comes down to it, your center line is one of the main reasons to keep you alive. Having a six-pack is awesome but in reality if its not strong and powerful, you're SOL my friend. Funny thing is, some of the strongest people in history didn't have six-packs yet lived for many years.
To build some solid, insanely strong abs and overall core is not crunches or isolated sit-ups. Unless you're in rehab or a beginner in exercise, crunches are more of a killer than anything else when it comes to Core Work. Most people people believe the Core is just abs, in fact from the bottom of your chest to your pelvis is the Core area. Those muscles working in unison develop a stronger foundation of health and fitness that virtually anything else next to legs, neck and grip. Isolating them is more cause for an injury than you were told about. You can do crunches till the cows come home and you'll never truly achieve mighty abs. Train the body as a unit with a main focus on those main areas; upper, lower and obliques.
The best exercises that I have found that truly hit these muscles are ones used in Gymnastics, Combat Sports & Sprint Training. Save your energy by learning exercises that hit all those muscles at the same time like Bridging, V-Ups, Sprinting Uphill, Side Planks, Full Body Sit-ups & others. Nothing replaces these because when you truly engage the core in compound exercises they put a mark on what brings out the very best within those muscles together instead of individually. The stronger your Core, the Stronger your whole BODY!!!
May The 4th Be With You,