Who said it was a contest?
We need both. Partnering each other, they are the symbiotic relationship needed for muscular-skeletal fitness.
Core stability training provides the framework – the hardware if you like. Cardio vascular exercise puts all this to the test, testing endurance and capacity of those very same muscles. In combination, both forms of exercise will mould the “body you need”, one that meets your day to day practical activities; ie strong back and core muscles for safe spinal posture (especially if you have a sitting job) or energy to keep up with your active day.
The “body you need” means having powerful muscles (or strong legs for lifting) that can be depended on 24/7; it means flexible joints ( pain-free knee and hips movement ) that that can be used 24/7 for bending. The more we use our bodies the stronger we become, the longer our bodies last. Yes we never “wear out”, provided we are mindful of careful, safe use of our bodies. And indeed we actually do “rust” away. If you don’t use it you lose it; such an annoying but true cliché.
Yes of course you need to be aware of how to move your joints with safety, how to posture your spine with the least wear and tear and you need to know the difference between good stretch and bad stretch. One is stretch, the other strain.
Core work ensures those muscles are strong enough to pump fuel (oxygen through blood supply) to the working parts and indeed you may ask the question – is there enough fuel getting through? Muscles that are challenged and exercised regularly – cardio work, respond to demand. With this increased demand (such as brisk walking, walking hills, swimming ) and over time, the body responds by extending new blood vessels. a more extensive vascular bed to the working parts. In other words, the beginnings of an improved blood flow throughout the body – to the muscles, the heart. In essence, the response to demand. Here we go again – if you don’t use it you lose it- sorry!! And yes, most importantly your heart. Being a muscular pump, it experiences this improved blood flow, making the pumping mechansim stronger, more effective and efficient..
So once fitness levels start to improve, more and more oxygen is provided to the working parts, improving efficiency and effectiveness of each muscle fibre. So the cycle begins. The more demand on our bodies the stronger we become, the easier it is to exercise; leading to increased cardio vascular fitness.