Negative-split strategies: Part two

If you begin a race with marathon pace and finish with 5km pace, likely this 5km won't be as fast due to fatigue, dehydration, and other factorsbut your average pace for the entire marathon will be much faster.

Question

Hi Gale,

I usually don't read the Active.com columns, but your recent one on negative-split strategies (http://www.active.com/story.cfm?story_id=13212) caught my attention.

I think you really know your stuff and provided useful information, but I don't think you went quite far enough. You mentioned reasons not to exceed a particular workload, as based on heart-rate and other measurements (assumption, power, etc...) but what you didn't mention is the connection between this and the negative-split.

My assumption is that you're saying we can gradually overload the body closer to the end of the race or event because we'll be done before it catches up with us? Or are you saying that as we get going, our bodies are able to do certain things better, and the limitations we have physiologically earlier in the race change (i.e. we can push harder before developing the "problems" you mention.

The article seems to be more about why you don't want to go past a certain level...burn too many matches, make too many withdrawals from the bank, etc... but doesn't mention the connection between this and negative splits.

Thank you for your time, and I hope you have the chance to respond. I know for myself, negative-splits are the only way to go, and this is for several "perceived" reasons.

First, despite the best of warm-ups, once you're in a rhythm you can eek out just a little bit more without going over your "threshold." (I know threshold is a concept that's up in the air at the moment...because it depends now on so many different factors.)

Secondly, it's a mental thing...if I'm at my "threshold," and I can feel it and know it, I know I'm already giving it all I've got -- to push any harder I'd be in BIG trouble. But if I run/ride/swim, etc. below my threshold, but then gradually turn up the volume, I'll feel like I have more left in the bank -- the perception being that I can go quite a bit faster. This helps me to relax, which in turn, DOES slightly raise my threshold (not fighting tight muscles, racing heart, etc.) and therefore I can gradually go faster and faster without feeling like I'm going to blow up. Then when I'm over the limit near the end, I am still mentally relaxed because I didn't tax my body and mind as much early-on; instead I was kind and gentle. So now when I need it, I can dig REALLY deep and push through to the end.

Just my non-scientific take on things. Of course, the longer I go, the looser I feel and the higher the watts go...for whatever that's worth as well. ~ M.S.

Answer

M.S. ~ Thanks a bunch for reading my column and for your thoughtful questions. Here is some additional information:

  • You are correct; we can overload the body at the end of the event because when we cross the finish line we're done. Let's look at a couple of examples.

    For example #1, if you are aiming to run a marathon and begin with an all-out-as-fast-as-you-can-go 5km, not only does your body need to recover in order to finish the marathon--but now you've affected the working cells and metabolism so that even after you recover, you won't have the same capability to run aerobically.

    In example #2, if you begin with marathon pace and finish with 5km pace, likely this 5km won't be as fast as the previous example due to fatigue, dehydration, and other factors--but your average pace for the entire marathon will be much faster. Also, as you mentioned, after this "fast" 5km the event is over, this is much easier to handle from the mental side of the equation.

    In example #1 you would likely have to walk or significantly slow your pace for some time in order to recover, forcing a slow average marathon pace. In addition to being painful physically, watching your pace dwindle can kill your spirit.


  • Your observation of needing to be warmed-up before you produce the most power or the best pace is also true. Key glycolytic enzymes work optimally at temperatures slightly above normal body core temperature. In the case of running, easy jogging followed by a transition to faster running raises metabolism, body temperature and improves circulation.

    Muscles also improve elasticity, allowing for a greater range of joint movement. Also, you've probably noticed that if you're doing intervals, usually the first one is not the best one. It takes a couple of repeats to get metabolic and neuromuscular speeds fired up.


  • Actual scientific studies on negative-split performances are rare. Typically, negative-split performances are analyzed post-race. In the book, "Better Training for Distance Runners" by Martin and Coe, they mention analyzing intermediate 5km split times during a marathon for a "fairly large population" of top-level distance runners. The athletes with fast splits early in the race, very often paid a price later on in the race with "dramatic" slow downs.

    Martin and Coe theorize that the following factors contributed to slowing: fuel depletion, increased viscosity of connective tissues and working muscles, concentrated blood from fluid losses through sweating, gradual decrease in oxygen delivery to working tissues and cooling of these tissues if ambient temperatures are sufficiently low.

I hope this helps you with more information about the connection between your body's performance and negative-split racing.


Gale Bernhardt was the 2003 USA Triathlon Pan American Games and 2004 USA Triathlon Olympic coach for both the men's and women's teams. Her first Olympic experience was as a personal cycling coach at the 2000 Sydney Olympic Games. Thousands of athletes have had successful training and racing experiences using Gale's pre-built, easy-to-follow training plans. For more information, click here. Let Gale and Active Trainer help you succeed.

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