When I swim freestyle continuously above my sustainable speed, the first thing which fails me is my deltoid - when fatigue set in I can no longer do a proper EVF catch and the exit is also affected as well.
However I've heard that the most used muscle in freestyle swimming is the lats, but I feel my lats only when I swim longer than 3k - by that time my deltoid have fatigued so much to the extent that it affects my swimming seriously.
What does the above symptom mean?
