A traditional, or regular plank, will have a greater emphasis on the transverse abdominis muscle, which is like an internal weight belt that keeps the core stabilized. The side plank will have a stronger emphasis on the quadratus lumborum - the part of the back side of the abdominal wall that plays a major role in preventing back pain.

While ab exercises like crunches and regular planks target the muscles in the front of your core, a side plank works your obliques, the muscles that run along the side of your core. Keeping your obliques strong can make it easier to rotate and bend your trunk.

The different plank types work on multiple muscles at once, such as rectus abdominis, external and internal oblique, forearms, erector spinae, and upper body. For example, standard plank targets the abs, and side plank works on oblique muscles, and hips, erector spine, and arms involved during each plank variation.