I'm not sure but yesterday I swam a mile in 50 degree water (with my wetsuit) and I was pretty tired even tho I usually do 3 miles in the pool. I guess staying warm takes energy. Felt great tho!
Last week I swam 1000 yards in a hot pool,...85 degrees and it sapped my energy,..it wore me out. A few days later, I swam 2.3 miles in 63 degree Ocean water,... and felt great. I wore no wetsuit,..merely kept moving,..it took an hour and a half,.I got out and had no chills. I ate well the night before ( shrimp,..salad, bread,.beer and a shot of scotch) and that morning had a bananna and hot tea. I was mentally "INTO" the swim before I started, and leaned into the harness during the swim,..it was fun! I do believe that a majority of the battle is in the mind.
