As a sports medicine physician I am often encouraging my patients to take to the water as a form of exercise. When people have injury or damaged joints and can not partake in their regular activity I suggest swimming as a first choice alternative. Triathlons developed when cross training with swimming and cycling was suggested to over-trained runners. Removing gravity and excellent exercise make swimming a sport of choice.
Although many of my patients report that they can swim they are uneasy with longer swims. Often this stems from poor technique. Often the lapse in technique is driven by their breathing mechanism. On land breathing is an afterthought: when we want air we breathe. In the water it is important to establish a rhythm to breathing that will meet our oxygen demands without impeding on our efficiency.
Speaking with swimming expert and former strength and conditioning coach for the Canadian team he mentioned that the most essential element to work on in freestyle technique is breathing.
Here are a few pointers:
Do you take a breath every second or third stroke? Depends on how you feel, it is important to be relaxed in the water, and 1:3 breaths is great for being aware of both sides of your swim, either for being on track or keeping an eye on competitors, but if you feel an urgency for air during that third stroke then go with 1:2 ratio and after a while switch sides. Furthermore a 1:2 ratio is favoured if the waves are forcing your head to far up on one side for a breath.
Now speaking of head, do not lift your head; the whole body should be rotating for the breath. Exhale in the water and roll the body for the breath for a natural stroke. Lifting your head causes the hips and legs to drop causing drag. Be sure to keep your self straight as possible from toes to top of head, extending the lead arm and avoiding cheating on your reach while taking a breath. Breathe in and concentrate on using your diaphragm more than the chest muscles.
Finally once you have taken your breath drop the top hip (the side that you took the breath from) to continue your fluid rhythm.
Once your face is in the water start slowly to exhale already, most through the mouth but a bit through the nose. As your reach the end of your two stoke cycle forcefully exhale the remnants in your lung, expelling the old air ready for a clean fresh breath.
Enjoy your training and your swim.