The plank is widely implemented in workouts, but for weight loss and muscle mass gain, it’s really ineffective. So why are we writing about it? Because if you are totally engaged in the plank, it becomes a yoga-esque exercise that can be effective in creating awareness of muscle engagement.
For example, planks performed with a lower back curve like the picture below are a sign of core disengagement:
Can you see her belly sagging? That is a sign of core that is disengaged. It makes the exercise ineffective, and pinches the lower back.
Just by drawing the belly in and rotating the pelvis towards the chest, a seemingly boring move like the plank can become challenging. This simple form correction can be good practice to take to other exercises. Our bodies tend to adjust and compensate in moves that are difficult, recruiting stronger muscles to take over muscles that are weaker, shifting bones and joints to get around tight muscles.
It is up to you to be aware of how your body deals with poses and exercises, and adjust yourself to make the move safer and more effective.