One of the most effective exercises when it comes to core conditioning and strengthening is a simple plank. To perform this exercise, lie on your stomach and place your elbows directly under your shoulders. Keep your forearms parallel. Bring in your core muscles by sucking in your stomach and hold steady. Lift up on to your toes creating a straight line through the shoulder, hip, knee and ankle joints. Don’t let your lower back arch, and keep your neck in a neutral position. Hold this position for approximately 30 seconds. Do three repetitions of the plank in a single session. Once you have mastered the plank and are able to hold for more than 30 seconds, you can add variations such as lifting a leg up while in a plank, or trying to balance your body (while in the plank position), with your hands on a gym ball/bosu ball.