Love this yoga excercise! Talk about core stretches? This is one of the best in my opinion! Nameste!
Here we go Inge! Lot's DO IT!! =-)
How to do it
Put down a towel, blanket, or yoga mat. Start by getting down on your hands and knees, then bend your arms and lower your elbows onto the floor. Keep your knees and lower legs on the floor and, working one at a time, slide your elbows out in front of you until your body is straight like a plank. Hold this position for 5 seconds.
Why it matters
Plank position is one of the best all-around yoga poses for engaging both abdominal and back muscles. The simple action of having to hold your body weight against gravity strengthens your abs and engages your back muscles. It also gives your shoulders a bit of a workout.
"Engage both your core and back muscles by stretching in the plank position"