The answer to this question isn’t easy, a lot depends on what your goals are along with what other types of training you do on a weekly basis. Nearly all workouts or activities involve using your core, when you run, do cardio, strength, boxing or many other forms of exercise, your core is getting (what I call) a secondary workout. Secondary - meaning, your core muscles are playing their part helping you achieve your goal but it’s not the primary muscle(s) that are doing most of the work.
So, let’s just pretend (for argument's sake), that this article is based on a weekly targeted (primary) core workout, with your goal being to strengthen your core region.
How often should you train your core?
Regardless of your fitness level, you should be aiming for 3 to 4 times per week with rest days in between. The reason why rest days are important is that recovery allows your body to repair and strengthen itself. Overtraining can lead to injury and your muscles becoming weaker.
I’m sure you already know that your core region incorporates your abdominals, obliques, back, and glutes, etc. Based on this my advice would be to design a core workout that hits your complete core and doesn’t isolate just one area.
When I design my Sub30 Core™ workouts I make sure to include the entire region and you should do the same.
I also recommend mixing your core training up as much as possible, doing the same workout promotes imbalances, lack of muscle growth and boredom.
Let me give you an idea of my simple but very effective weekly core workout:
Monday/Wednesday/Friday:
Sub30 Core™ workout (20mins) followed by a 5-10 minute plank.
That’s just 90 minutes per week.
Finally, don’t fall into the trap of just focusing on your abdominal region in a quest for a better definition. Your goal should be a stronger core, not a six-pack.