The four-point plank is the standard plank exercise. Done correctly, this tried and true exercise has been shown to actively recruit many core muscles including the rectus abdominus, internal obliques, erector spinae, multifidus, latissimus dorsi, and glute max and medius.
However, as one continues to perform this exercise, it can become less challenging over time. So instead of trying to break the new world record for longest plank held of 10 hours, 10 minutes ( see video here ), try adding these variations in time frames that fit your programming.
-Long Level Posterior Pelvic Tilt Plank (pictured above): Start in regular four-point plank but move your elbows closer together (6 inches) and move them up to nose level. Keep arms and hands in a neutral position (thumbs up). While performing the plank, squeeze the glutes to achieve a posterior pelvic tilt.
-Pull Down Plank: This plank sets up exactly as the standard plank. Elbows directly below the shoulders, hands in a fist and holding neutral spine. The difference here is when the clock starts, with the forearms still in contact with the floor, pull the elbows down and back. The shoulders may move just slightly over your elbows but don't go too far. Try to maintain that pull down action through the duration of the exercise. For even more intensity add a forced exhale as you pull.