Thursday, April 29, 2010

Looking Forward and Looking Back

I've had a couple great runs in the VFFs, but haven't been able to post for awhile. The iMac is once again at the Apple Store. How many geniuses does it take to fix a faulty temperature sensor?

I'm getting faster!

This Monday I went out for my 7km loop from work. It felt pretty fast. While it wasn't exactly effortless, I felt like I had much more gas in the tank at the end of my run. I could pick the pace right up and hold it longer. For the first time in a long time I was passing some people. In the last third of the run I was able to kick it back into gear and have fun instead of just trying to make it back.
After the run I wanted to confirm my thoughts and double checked my pace. It turns out that the last time I was able to hold a 5'09"/km pace was November 3rd, 2007. That was a 16km leg of the Haney to Harrison Relay race. So in the 160 runs I've logged over the last two and a half years, I've not held the pace that I was able to on Monday. I've had periods of very active training during that time: at least as focused as I've been over the last month. For instance look at the monthly runs graph from my current Summary Statistics:
Note that June of 2008 was very similar in terms of distance to now (April 2010), other than the fact that I had a better preceding month in '08. But the fastest pace I could hold in June 2008 was 5'20" over 4km. I'm a little faster now, over longer distances, with slightly less training. The speed isn't that different, so maybe I'm splitting hairs. But, I went out again on Wednesday and came back with an even faster time:
Ok, ok... four one hundredths of a second per kilometer. I really am splitting hairs here. This falls well within the margin of error of the Nikeplus iPod gadget. Still, says it is an improvement and I'll take what I can get.

I really think running in the VFFs is making me faster. Two people I've mentioned that to have said that it is probably just enthusiasm. To that I reply "either way, I don't care as long as I'm getting faster!" But I really think there is more to it than a love of new gear. Running in the VFFs is not a little different. It is a lot different: completely different. I certainly welcome the sharp uptick in my Pace over Time graph.

While it is tough to compare running with my Asics to running in the VFFs, my gut feeling is that towards the end of my run I've got more gas in the tank and can hold a quicker pace while I'm tired. It turns out there may be something to it...

A nice find on the inter-tubes...

I recently came across a fantastic paper on barefoot running that pulls together information from many different sources. You really should read Why Running Shoes Don't Work by Steve Magness. It includes information from studies that show (among other things) that the cushion of shoes may cause harder impacts than no cushion, etc. But, the thing I found most interesting backs up my gut feeling about having more energy later in a run.
Running shoes do not utilize the elastic storage and return as well as barefoot or minimal shoes. More energy is lost with shoes than with barefoot running (Alexander and Bennett, 1989). In addition, in some models of shoes, the arch is not allowed to function like a spring. The arch of the foot can store around 17% of kinetic energy (Ker, 1987). Given these results, its not surprising that running barefoot when compared to running with shoes is more efficient. Several studies have shown a decreased VO2 at the same pace with barefoot running, even when weight is taken into account. This should be no surprise as I mentioned above, without elastic recoil VO2 requirement would be 30-40% higher. Running in a minimal shoe allows for better utilization of this system.
 So I'm not crazy!

Well, let me qualify that... In this instance there may be data that corroborates my perceived increase in cardiovascular endurance while running in minimalist shoes.

Looking forward, looking back.

Running in the VFFs has me exited about running again. If I continue to improve I could have my speed back to a reasonable clip pretty soon. Can I ever reach that 44'22" 10k PR? I guess we'll have to wait and see. For now, my goal is to simply complete the Vancouver Sun Run 10k. I'd like to keep it under an hour but just running a 10k in the VFFs is good enough. I can't help but think, given the pace of my recent runs, that I could improve my time over the last couple of 10ks I've done. My Sun Run time last year was 57'52" Guess I'll find out in a couple weeks.

So, what's the downside?

I'm not sure it is really a downside, but I've been surprisingly sore. I guess it stands to reason that I would be. I've been wearing the same Asics GEL-Kayano model shoes for many years. These are as structured and cushioned a shoe as you can get: thick heel, squishy foam, motion control, shock absorbing gel, arch support. They have been doing much of the work that my muscles, bones and arch should have been doing, and I have some developmental catch up to do. Like wearing a cast, the muscles haven't been able to their job, and have atrophied.

At least I hope that is all. I'm sore enough that I'm worried a bit about injury. When I wake up in the morning I can't actually walk. I hobble around favoring my left foot, wondering how I'm going to get through the day. But unlike other soreness I've had, it works itself out pretty quick. A few minutes of movement and I can walk OK. A few more and I'm fine. Every time I get up I go from thinking I'm actually injured to feeling fine in a very short time. It is different from other pain I've had. If my back hurts like that, I know I'll be out of commission for awhile. My quads or other muscles, 2 days. It is very odd.

My current plan is to take a couple days off, and maybe try to get a run in this weekend that is more than 7km.

We'll see how it goes.

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