1 hour postal swim

I had an interesting eye-opener yesterday. Two weeks ago, I did the hour swim, and exceeded 3 x 1650s by about 45 yards. My 1650 splits were: 20:02; 19:51; and 19:35. The amazing thing for me was I never got all that tired; I didn't expect to swim that far, so I tried to just stay within myself and swim by feel. If I found so much as a tiny *** of lactic acid, I would back down. I also did not realize at the time that each successive 1650 was getting faster. It felt as if I was pretty much holding the same pace throughout, which is, I suppose, a testimony to the ability of a "warm up" to enhance distance performance. (When doing an hour swim, I don't do any official warm up--the first part of the race itself serves this purpose.) Anyhow, yesterday, I swam in a local 1650 meet. I figured I could go out a lot faster because it was so much shorter an event than an hour swim. I ended up swimming an 18:59.22--good for me, but not quite as good as last year, when I first turned 50 and swam an 18:53. Anyhow, when I compared this year's 1650 splits to last year's, I saw that I was about 5 seconds faster this year at the first 500 (i.e., a 5:41 this year vs. a 5:46 last year); and still a little faster (by about 1/2 second) at the 1000 mark. But the third 500 of the race, I lost big time compared to last year--adding what would prove to be the 5.5 seconds difference for the overall event. My teammate thinks I went out at the right pace and just wimped out on the middle and third 500s; I think that I went out too fast, and that if I had held back a little more at the beginning, I could have finished stronger. I know everyone is different, and that some like to positive split a distance race, some like to hold an even pace, and some like to negative split it. What do you experienced distance swimmers find works best for you? Do you think I would have had a better overall time if I had saved a little more on the first 500? Thanks for any advice. PS I was MUCH more tired at the end of the 1650 than I was at the end of the 1-hour postal swim.

I had an interesting eye-opener yesterday. Two weeks ago, I did the hour swim, and exceeded 3 x 1650s by about 45 yards. My 1650 splits were: 20:02; 19:51; and 19:35. The amazing thing for me was I never got all that tired; I didn't expect to swim that far, so I tried to just stay within myself and swim by feel. If I found so much as a tiny *** of lactic acid, I would back down. I also did not realize at the time that each successive 1650 was getting faster. It felt as if I was pretty much holding the same pace throughout, which is, I suppose, a testimony to the ability of a "warm up" to enhance distance performance. (When doing an hour swim, I don't do any official warm up--the first part of the race itself serves this purpose.) Anyhow, yesterday, I swam in a local 1650 meet. I figured I could go out a lot faster because it was so much shorter an event than an hour swim. I ended up swimming an 18:59.22--good for me, but not quite as good as last year, when I first turned 50 and swam an 18:53. Anyhow, when I compared this year's 1650 splits to last year's, I saw that I was about 5 seconds faster this year at the first 500 (i.e., a 5:41 this year vs. a 5:46 last year); and still a little faster (by about 1/2 second) at the 1000 mark. But the third 500 of the race, I lost big time compared to last year--adding what would prove to be the 5.5 seconds difference for the overall event. My teammate thinks I went out at the right pace and just wimped out on the middle and third 500s; I think that I went out too fast, and that if I had held back a little more at the beginning, I could have finished stronger. I know everyone is different, and that some like to positive split a distance race, some like to hold an even pace, and some like to negative split it. What do you experienced distance swimmers find works best for you? Do you think I would have had a better overall time if I had saved a little more on the first 500? Thanks for any advice. PS I was MUCH more tired at the end of the 1650 than I was at the end of the 1-hour postal swim.