The plank is an effective exercise to strengthen your abdominal and back muscles. It is a great test of your current strength as it requires a stillness of the body and a calmness of the mind.
Position yourself in the upright press-up position and engage your abs. Breathe steadily and deeply as you concentrate on maintaining your form. It is important to visualise your strength and not sag the hips as this strains your lower back muscles.
I enjoy the plank as there are many variations and it relies on your concentration.
Longest in position – 5:22
Longest in position one side then the other – 1:00