PLANK
Lay face down on the floor.
Place your arms so that your shoulders are right above your elbows and your wrists are in a straight line with your elbows.
Hold the position as long as you can by tightening your stomach muscles and glutes (the muscles that make up your buttocks). Increase the position holding time gradually.
Between each set, take about a minute to rest.
Keep going as long as you can.
