The benefits of a plank

Targets multiple muscles

“When you really are mindful of your form, the plank targets muscles way beyond your abdominals. It will activate your hip flexors, quads, glutes and delts as you’re squeezing in the hold and keeping yourself away from the floor,” says Emma.

Great time under tension

“When holding a plank, the work is constant,” says Emma. “In a crunch, you give the abdominal muscles a slight respite as you reach the floor, but in the plank you are just holding continuously.” That means that the muscles are under tension for as long as you hold the exercise, leading to “strength, balance, and endurance gains,” according to Emma.

Extra challenging variations

In a 2013 study by Les Mills Lab, researchers found that “abdominal and lumbar (back) muscle activity was greatest when balance was challenged, by adding complex movements to these traditional core exercises.” Essentially, adapting the plank leads to even more core engagement, while still working on multiple muscles. For example, a plank with a knee lift toward the opposite side of the chest increases ab activation by 30% and oblique activation by 20%. Plus, a plank with hand reach gives 20% more abdominal activation than a crunch.

Less risk of injury

Many people find that they struggle with low back or neck pain when attempting the crunch. “It can be easy to get the form wrong by lifting through the shoulders and straining the neck. Bad form can also result in feeling uncomfortable throughout the spine,” says Emma. While it’s important to keep your form perfect in plank too, there’s less risk of doing damage as there’s less compression of the spine, according to a 2018 study.

Crunches vs plank: what is most effective for a stronger core?