Racelle Reed, manager of training development at Pure Barre, says planks work your rectus abdominis, erector spinae, glutes, quads, and delts.
Deadlifts win. Deadlifts are one of the best abs exercises for women.
The ab wheel is a good ASOT product. Mary Nnamani, Blink Fitness personal trainer, says the ab wheel is great for core strength.
Joe Dowell, C.S.C.S. recommends cable Pallof presses and planks for beginners. He recommends this TRX move for advanced fitness levels.
Hilton Head Health fitness director David Chesworth prefers the hollow tuck hold over a plank, especially for beginners. "It's hard to do this wrong without feeling it in the abs."