Targets: Lats, back, abs and core. Beginner: Perform alternating knee hugs.
Targets: Transverse abdomen, rectus abdominis, lower abs and hip flexors. Beginner: Omit the crunch.
Targets: Deep transverse abdomen muscles, rectus abdominis, oblique muscles, shoulders, back, legs, glutes and quads. Beginner: Bird dog.
Targets: Rectus abdominis, transverse abs, and lower abs. Beginner: Shorten range of motion by bending the legs.
Targets: Abs, core and back. Beginner: Omit the reverse crunch and perform seated alternating jabs.