This bit of great swim science from our swim-technical advisor, Dr. Rod Havriluk of Swim Technology Resourses (STR):
The best swimmers in the world are racing at a speed of 2.1 m/sec - certainly not an easy feat. This speed requires a far better than average technique and considerable strength (as well as super conditioning and expert coaching).
A formula (the drag equation) is useful for calculating how strength and technique contribute to speed. When applying this formula, technique is measured by the active drag coefficient (Cd) and strength by hand force. The calculations shows that a swimmer with a Cd of .8 (where Cd = 1.0 is average) must generate an average hand force of 40 lbs (180 Newtons) to swim 2.1 m/sec.
Are you strong enough to generate an average force of 40 lbs? Keep in mind that swimmers often waste one-third of the stroke with the arm in a weak position that generates very little force (less than 5 lbs). Typically, a swimmer must be capable of a peak force of 60 to 80 lbs (with each hand) to maintain an average force of 40 lbs.
How effective is your technique? By the way, if your technique “looks good,” that probably only means your Cd is around 1.0. A Cd must be quantitatively measured, and cannot be qualitatively eyeballed.
So, what is necessary to go faster than 2.1 m/sec? Swimmers can work on traditional methods to improve both their strength and technique so that average force is greater than 40 lbs and Cd is less than .8. However, probably the most neglected area for performance improvement is arm synchronization.
A .1 sec change in arm synchronization can increase the average hand force by almost 7 lbs. Unfortunately, many swimmers practice an antiquated counterproductive arm synchronization – resembling catch-up stroke - that results in gaps in propulsion and a lower average force. A more continuous source of propulsion yields a higher average force without having to get stronger!
Now, in the past, we have taught and instructed “catch-up” drill in the context of body-balance and to instruct a hip-initiated stroke mechanic.
But as the athlete’s balance and core-stroke-activation improve…….the science is pretty clear that NOT losing your momentum is, by far, the best way to sustain speed in the dense medium of water.
In other words: a catch-up centric stroke WILL help to teach you how to engage your powerful core muscles…….but once you have neuromusularly “learned” this…….catch-up will only allow you to swim so fast. {Particularly in the more choppy, open water medium.}
Swim smart.

STUDIO 7 MULTISPORT