On the Floor, holding onto an object for stability. Leg Raises are a great exercise to challenge the lower abdominals and hip flexor muscles.

Hip Hikes add a difficult variation to exercise the abdominals and lumbar muscle groups. Leg strictly vertical, the action requires lifting of the pelvis from the floor and lowering with control.

In addition to the leg raise or hip hikes alone, combining these creates a difficult exercise to develop trunk strength.

A difficult exercise to control, the barbell rollout challenges trunk and upper limb strength and coordination. It requires adequate strength levels and shoulder mobility to execute to range.

Rotary straddle bench twist exercise with increased difficulty by leaning the torso back to 120 whilst straddling the bench or locking feet into DB (as seen in video). In this position fully rotate around the spine to increase strength at range through the anterior slings whilst challenging trunk strength.

To add difficulty to a Sit Up or Incline Sit Up, suspend the torso from a bench or GHD.

Increased difficulty to the Russian Twists, by suspending the trunk off a GHD or Bench.

Combination 2in1 exercise of Suspended Sit Up with DB Fly. It has a moderate to high degree of difficulty. This will strengthen your abdomen thoroughly.