The best swimming style depends on what you want from your workout. If you want to build strength and endurance, go for the freestyle and the butterfly strokes.
Swimming for Muscle Building: Targeted Muscle Groups & Strokes
Weak Stroke/Best Stroke IM Set – The Swimming Wizard
How To Swim Freestyle With Perfect Technique
Maximizing Swimming Performance in the Gym: The Myth of Sport
Triathlon Swimming: Best Swim Stroke for a triathlon
Freestyle Swimming – 10 Tips to Improve Your Technique
Rhythmic Breathing in Swimming Triathlon training, Triathlon, Breathing techniques
30 Minute Strength Training Workout For Swimmers
Ask Well: Swimming to Ease Back Pain - The New York Times
Swimming May Be the Best Exercise to Lose Weight
I'm 65 and never learned to swim, but would like to for exercise
