The average swimming book prescribes stroke techniques, then offers a sample training routine. In 'Breakthrough Swimming', Cecil Colwin sets his stroke and training advice amid much firm background and some speculative discussion. Coach Colwin covers three subjects: History, Hydrodynamics and Training.
The history is broken into two parts which begin and end the book. The first is a history of swim technique (sidestroke, trudgen, overarm, etc.) which leads to a description of the four current strokes. As in Swimming Dynamics, he illustrates a "typical" way of swimming each stroke even though he admits a wide range of technique possibilities. (Colwin is an excellent draughtsman, but there seems to be a drawing error: In the text and in his side view drawings of the crawl, he describes a full body rotation of 35 - 45 degrees each way as desirable. His front view, however, shows the swimmer almost dead flat throughout the crawl.)
Continuing the exploration of hydrodynamics that he began in Swimming Dynamics, Colwin discusses the bow wave, lift, his vortex-shedding theories of propulsion, strategies of streamlining, using the hands to direct the water and many other ideas.
In covering training, Colwin (and Pyne) offer the usual ideas of aerobic vs anaerobic, interval vs distance, etc. I find myself thinking of his section, "Development of the Will to Overcome Fatigue," as I swim. I realize that I have rarely reached Hurt, much less Agony or Pain since high school (at least not in the pool).
The book ends with a history of competition that discusses rule changes, better pools, the World Cup tour (he's not impressed), national team vs club-based coaching, a chronicle of doping, fistgloves, the problems with bodysuits, a ranking of the stars of the 20th century and a look forward.
I definitely found the book worth reading.