Why strengthen your core? Your core or torso is your link between the upper body and the lower body. You can't transfer the strength of your lower body, the most powerful muscles in your body, to an oar in your hands with a weak core. Examples of ineffective power application caused by a weak core are when the body collapses as the oar comes to the body, or if you shoot your slide because the back can't handle the power generated from the legs. Leaning to one side in the boat can also be caused by weak core muscles.
The core muscles are located between the hips and chest. These muscles include the rectus abdominus, obliques (internal/external), transverse abdominus, quadratus lomborum, spinal erectors and the multifidus muscles. The core muscles are responsible for flexion and extension (front and back movement). They also move the body laterally (side to side). They rotate and twist the body (like sweep rowing), and they stabilize the body.
How do you strengthen the core? In order to strengthen the core you need to train all movements: flexion/extension, lateral, rotation, and stabilization. Training just one movement such as doing crunches only trains flexion/extension. You need to train all 4 areas to improve core strength.
How often should core training be performed? We recommend training the core 4x per week. An example of how to break up the days would be: Day 1 - flexion/extension, Day 2 - rotation, Day 3 - lateral, and Day 4 - stabilization. You can take a day off between Day 2 and 3. Another example would be to pair up two of the movements each day such as flexion/extension and rotation for Day 1. On Day 2 do lateral and stabilization exercises. You can then take a day off and then repeat sequence.
When doing any exercise, start off with simple exercises that are easy to do. Change up exercises every 3-4 weeks to make more challenging. Remember that core training is done to help prevent injuries, not create them so start easy and don't do an exercise if you are unsure how to do it.