In the last USMS Swimmer magazine, there was an article depicting a swimmer showing perfect streamline, one arm extended, form in the water. She was practicing the extension to pierce the water in as needle-like form as possible, and practicing to maintain this form. One thing they talked about was the fact that her head in the correct position resulted in her cheek being against her shoulder while her arm was extended forward into full extension for the stroke.
I have form that really falls apart when I try to swim faster, and also when I get tired. I really wanted to improve my ability to maintain perfect streamline form while swimming at high stroke rates. To that end, I began swimming like the woman in the article and making sure my arm was fully extended and that my cheek would touch my shoulder briefly before I began my stroke. The other thing I began doing was breathing only once every 4 strokes. This allowed me to hold my head in a stationary position and not be disturbed so much by taking a breath. I could rotate my body back and forth along the line dictated by my head and neck and make sure everything was in line and not swaying back and forth, causing drag.
So I began swimming that way. Certainly taking less breaths was challenging, but I seemed to have gotten used to that by now. If I need to take an extra breath, I'll take another breath after my last one and then go back to once every 4 strokes. But it does help me to relax and try to be very efficient in the water.
The other thing I noticed was that by touching my cheek to my shoulder, it made sure that my arm was fully extended on each stroke. Pulling so much while having my arm extended caused knots to form in my serratus and lats, and my pecs began to get sore as well. I am sure this is my body's way of adjusting to the more extended stroke. It also made me realize how short my strokes really were, and how more efficient they could be.
I dealt with the knots with lots of ART and some reduced swimming until my muscles adapted.
The result: I am more easily maintaining fairly fast (for me) swim times for 50 and 100 meters. I am finding that I can keep a faster speed for a longer period of time, than the way I was swimming before this cheek to shoulder/less breathing method. Keeping my body in a better streamline was also helping me maintain speed and not lose speed between strokes.