I am looking into a wide variety of workouts to keep from getting boredom. There is a term that seems to be thrown around here: core training. My question is what is it and who should be doing it? Is it advanced and hence only for the very athletic?
Your core is the neck, abdominal, back and hip muscles which are used for stability. In a very real sense, your strength can be limited by your core. In fact, a large part of your power production comes from your core strength.
Core training is strengthening your abdominal and back muscles to provide more stability for the rest of your work. It's a critical part of training, and everyone should have some core training in their regimen. Anyone who exercises should keep their core strong because working extremities without using core muscles leads to excessive strain on your extremities. An imbalance of core and extremity work can cause core (back) and extremity pain or injury.
As to the specifics, it depends on the rest of your training. Someone who is working toward a 400lb squat and 500lb deadlift will need more core strength than someone who is focusing on body weight exercise.