In a thread on the TI Discussion Forum Andreas posted  this closeup of his torso taken from video of his freestyle stroke, drawing attention to the drag-producing water vortices apparently created by curvature in the lower spine.

He commented: “My abdomen is relaxed, when it should be tense to draw my spine straight. When practicing in front of a mirror, I really have to maintain massive abdominal tension to reduce the arch. Today at the pool, I had some success, by telling myself I was not swimming but making a bridge.”

Katie and Alan both advised Andreas to focus  on releasing his head to a neutral position before focusing on core muscles. TI Coach Suzanne Atkinson added that “some focus on contracting the abdominals . . . will aid in all the fundamentals . . . connecting the pull with rotation with kick and even breathing, tightening your body position and unifying the actions.”

This is all advice worth taking to heart:
1) Releasing your head to a neutral position should solve most issues with excess lower-back curvature, reducing the amount of ab activation needed.
2) Creating tone (not tension) in the core should be directed more at stabilizing the bodyline overall, and with improving integration of all elements of the  stroke.

This got me thinking about how I’ve trained and thought about core muscles in relation to swimming, and specifically to freestyle technique.

I regularly  do many hours of dryland exercise, like the bridge illustrated above, plus yoga. I do those as much to keep my back strong and supple–though spending many hours sitting at a computer desk–as to benefit my swimming.  I’ve sometimes compared the ‘core engagement’ I feel while doing dryland exercise to what I feel while swimming. I feel my abs working much more intensively during land exercise  than while swimming.

On a few occasions I’ve  thought of ‘pulling in my belly-button’  or ‘tucking my tailbone’ while swimming. As “Stroke Thoughts” I’ve found those interesting, but not sensed significant change in my stroke as a result.

On the other hand, what I’ve found more revealing are times when I’ve simply paid attention to abdominals as I swam, to bring what’s happening naturally from my subconscious to conscious awareness.

When I first did so, I was surprised to discover a striking level of abdominal tone, despite not trying to contract them. My immediate reaction was “Hey, this is a pretty good ab workout.”

After later reflection, my intuition was that tone in the core most likely resulted from hundreds of hours of thinking about Active Streamlining, including such thoughts as:
1) Fit through a smaller ‘hole’ in the water.
2) Use the extending arm to lengthen the bodyline.
3) Keep the bodyline long for a extra nanosecond in each stroke.
4) Make less noise, fewer bubbles and smaller waves.
5) Line up each side of my body to follow the spearing arm through the ’sleeve’ it makes.

In other words, thinking consciously of an image like the one below- as well as practicing the variety of drills and Stroke Thoughts that produce this kind of alignment – will ensure that every length you swim will also give your abs a good workout AND fire a larger and more integrated network of circuits in your brain.