Negative Splitting and Neurology

[Jeff Linger]

I'm starting this as a new thread because I think there's some stuff in this that tangents away from the specific category of 5k v. 10k racing, however, it is in response to the discussion that started there. I've personally never, ever been a fan of even splitting. It might just be me, but my body continues to warm up until it has reached the point of exhaustion, at which point it drastically falls off the pace. Almost every race I've ever run (the marathon being the exception where I fell off pace about 20 secs/mile with 5 to go) I've always run negative split. This includes when I qualified for Nationals in the 800 meters in 1989. Even in this race I went out firm and comfortable through the first half, hit the 3rd quarter of the race hard and driving and then tried to keep that pace continually increasing through the finish. The result was 4 successive 200 meter negative splits. I think that a shorter race may demonstrate more poignantly the importance of negative splitting. An even paced race is run (if the intention is to run the best you possibly can on that day) essentially right on the bonk line the whole way. You have to know exactly where that line is for the distance you're running and then ensure that you keep pressed right up to the limit without going over. On the other hand, an intelligently run negative split race may give you a better chance to ensure that you press the limit without breaking yourself into a bonk mode too early, thus allowing you to deal with serious fatigue for a shorter period of time, even if it is potentially a higher level of fatigue. Put another way ... "A negative-split strategy utilizing heart rate and pace as tools for time-trial-type events, such as non-drafting triathlon, helps us manage the production and elimination of acid within our cells." In a shorter race run at significanly faster paces if a racer has a breakdown it becomes more readily visible. If you want to look at more of the details of this you can see them here http://www.active.com/triathlon/Articles/Negative-split_strategies.htm. Here is a basic over-view on negative splitting and how to train for it http://www.runnersworld.com/article/0,7120,s6-238-244--12106-0,00.html and here is an article that will help you understand negative splitting better by showing you how the Kenyans are often able to positive-split a race http://www.pponline.co.uk/encyc/0837.htm -- note to most FRBers who live at altitude - you're living in an environment that may be helping your body be more equipped to deal with fatigue in such a way that with the right training you might be better prepared to positive split a race [this won't necessarily lead to a PR, however, it may actually interfere with your opponents racing technique in such a way as to tip the race in your favor over a potentially faster runner -- note, you'll have to change your training techniques]). I'd really like to hear from Sasha regarding this last article because I know he is often conscientious about neurological breakdown that occurs from too much intensity training. Note, this last article is rather scientific so if that's not your thing you might want to skip to the article summary.

All in all, it appears that your splitting technique depends on what you've trained for and a personal choice: Do you want to deal with a fatigue factor for a longer period of time at a steady stress level, or do you want to deal with fatigue for a shorter period of time at a more intense level.

[Sasha Pachev]

My take on this. If your are limited by cardio or fuel, even or negative split will produce the best result. If you are limited by something else, this is not necessarily the case. Of all my current PRs I can think of only one (loop course 10 K, 32:59) that was set with a negative split. And we might have had tailwind in the second half of that one - most people than normally do not negative split managed a negative split in that race. So it may not have been a negative split after all.
Needless to say, in 23 years of racing I have made attempts to start out slower, but was never able to speed up in the second half unless I started way off pace.

[Jeff Linger]

Sasha, I don't know if you read that last article pertaining to the Kenyan's and positive splitting preparation based on intense training, but, this question is based on that article and some other times when I've heard you mention the neurological side of matters. When I was preparing for my marathon you suggested that perhaps I was running too many of my miles at too fast a pace (Almost every one of my long runs was done at race pace). You suggested that the majority of my miles should be run around the 8 minute/mile pace. (I was shooting for 7:15-7:30 pace for my marathon). I believe your rational had to do with nuerological needs associated with increased stress from too many miles at too fast a pace. Can you comment on your thoughts about what you think would happen if the mileage were cut down and the intensity beefed up? What if you cut your mileage by, say, 1/3 and increased your intensity workouts by some sort of equivalent match to the reduced mileage (when I say you, I actually mean you not just 'everyman' or woman).

[Sasha Pachev]

Jeff - most runners that do not run more than 50 miles a week are limited by cardio or fuel. Those things are easy to fix - for cardio, just run more miles. For fuel, running more miles helps, but so does running at marathon race pace for 8-15 miles. Why not run marathon pace every day? Problem #1: injury risk. Problem #2: once you are in shape, marathon pace starts putting some serious strain on your nervous system. Also, aerobic benefits are essentially the same at a wide range of paces and are largely a function of how far you go. So you maximize them by picking a pace that allows you to go the longest distance for the day with the minimum damage in the injury and the neurological department.

A runner that is so fit aerobically that he is limited by the neural drive can benefit from cutting the mileage and increasing the intensity, but not to the point that he loses his aerobic conditioning enough for it to become a limit.

I did read the article on the Kenyan runners. Good points, but too much speculation without measurements to back it up, and a hasty jump to conclusions about how to change your training. I really do not like it when a scientist tries to reduce the complex process of running to muscle chemistry. Western scientists keep studying hydrogen ions, lactate levels, VO2, and sodium/potassium pumps. Africans just run by feel, and they win. What that tells me is if you want to succeed, your feel must come first. Measurements are good, they help understand the feel, but they mean nothing without the feel.