Core strengthening is a popular choice for improving athletic performance, preventing injuries, and reducing pain.

Level 1 is the basic core contractions. Being able to brace your abdominals.

This is often easy to achieve with volitional bracing, crunches, and or planks.

Level 2 is a much more difficult, but important level to attain. It involves being able to reactively contract your core on top of already active core.

It’s being able to create an internal pulse to achieve and external one. This is often seen in sports. Where a golfer or puncher will have their core active, but pulse their core up a notch right before they strike the ball or opponent.

This allows for the ability to stay loose for most of the movement, but create effective stiffness when it matters most.

Because if you’re maximally contracted the whole time, you can’t be fast. Nor would it be energy efficient.

It’s analogous to a manual car. You can’t drive if you’re always in 5th gear. You should be able to shift up and down according to what the road needs.

Your core is no different.

I personally think this is what makes the greats so elegant. Watching Muhammad Ali, Roger Federer, or Michael Jordan you can see the balance of fluidity and strength.

Even studies are showing that this type of core training is effective.

https://onlinelibrary.wiley.com/doi/full/10.1002/tsm2.191

https://pubmed.ncbi.nlm.nih.gov/29052033/

And one of the world renowned spine researchers, Stuart McGill, has been advocating this for years.

So after you get level 1 core training, make sure to work your way into level 2.