Went to the Provo River Trail by Geneva Road to check my condition. Planned a 5 mile tempo run starting out at 5:30 pace to see how long I'd be able to hold it, and what will happen afterwards. Warmed up 2 miles. Then started the tempo towards the Utah Lake. Flat course. Splits by the quarter - 1:22 - 1:23 - 1:24 - 1:24 (5:32) - 1:25 - 1:25 - 1:27 - 1:27 (5:44) - 1:29. After 1:29 I figured there was something seriously wrong, and decided to stop. Jogged some more, did 4x100 strides. Then went home, and ran some more with the kids. I've had similar experiences before, but not so drastic, where 5:30 pace feels easy on the first mile, and then deteriorates to 5:55 in a mile, while the effort feels the same, and other than slow splits, nothing really appears to be out of the ordinary. Actually, it has been this bad before once - Thanksgiving 4 miler in 2005. One could blame it on the legs being tired from the mileage and the marathon, but I think this is only a part of the story. When it is just the legs, what happens is that I cannot start at a good pace, but whatever pace I start at I keep. Besides, it takes quite a bit of beating to get my legs to go 5:55, and the legs did not feel tired. In exercise physiology, when they have excluded the muscle itself as the limiting factor of performance, they blame it on the central nervous system fatigue. This is quite possible. Right before the Thanksgiving 4 miler, I ran with every one of my kids in their races first before starting mine. With the oldest child being 6, and the number of kids being 4, this did cause quite a bit of load on the central nervous system. And did did show in the race - my splits were 5:10 - 5:19 - 5:51 - 5:26. I would have called the third mile long had I not run most of it earlier during the first lap, and had it not been marked by the quarters. Something just quit for 5 minutes, and I am quite certain it was not the muscles or the heart. Perhaps the experience today is a blessing in disguise. In the past, I used to pray before a workout that I would be able to reach a particular time goal. But recently I decided to pray so that the workout will be for my benefit to help me reach my long term goals. Perhaps this drastic slowdown is an answer to my prayer highlighting a limitation that I have been neglecting somewhat. I keep working on my speed, muscle strength, heart, glycogen stores , but if the brain cannot give enough spark, all that work does not help very much. Now assuming that the problem is indeed what I think it is how do you get the brain/central nervous system to be more robust? | 