Training the core is important for any athlete, when it comes to the core don't just think 6-pack, but think of the core as a unit, made up of an inner and outer unit. The inner unit provides stability and the outer unit provides movement. The inner unit is comprised of the transverse abdominis and oblique muscles--they stabilise the trunk before movement initiates. When we move or there are sudden changes the core contracts to stabilise the body to stop us from toppling over. Additionally, the core transfers force between the lower and upper body, therefore a stronger core can allow you to produce more force when sprinting, jumping and lifting. The core also flexes the spine to, so explore the ranges that your core offers without limiting your movement due to limited beliefs. The best core exercises are those that train the core indirectly, whilst you move the limbs, you keep the core braced, this is a lot more effective. In a weightlifting context, breathing in, hold and and bracing the core can provide intra-abdominal pressure, which will go onto stabilise the spine more effectively during your lifts.