Thursday, November 15, 2012

Running AND arithmatic.... it sounds as if this will be an ugly post!

As posted previously my swim has improved considerably and I think I have a pretty good idea of what I need to do to continue to improve my technique during the off-season.   A popular addage for improving bike times is "TITS" (time-in-the-saddle - basically, if you want to get stronger, ride more!) - I can do that!  But what about running?.....

Yeah, right!
There's something to be said for the running equivalent of "TITS" - just get out and run more!  That will certainly pay dividends if I start ramping-up mileage again in the new year, but during the off season I need to give my legs some rest.  Not only that, but I know that my run technique is pretty poor.  I am probably well described as a "plodder" - a carthorse!.  I can churn out the miles, but I never look the same as those annoyingly effortless, lythe runners who simply glide gracefully around the planet seemingly flying and barely making contact with terra firma.  What the heck do they have that I don't?

Well, one thing is almost most certainly less weight, and I'm going to address that during the off-season, but it's more than that.  There are guys who weigh the same as me who are much smoother and faster runners and also smaller guys who seem to "plod" like I do.

The next popular issue for discussion at the moment is foot strike.  In addition to being more likely to avoid injury, mid foot strikers are apparently also likely to be faster than rear foot strikers (or "heel strikers") for the simple reason that they spend less time in contact with the ground, where resistance slows you down, and more time "flying".  Joe Friel talks a little about it here and it will only take about two nanoseconds on google to be completely overwhelmed with articles on barefoot and natural running; low profile running shoes; foot striking and so on.  Now, as it happens, several coaches and the guys at Bull City Running have analyzed my foot strike and, by pure luck I guess, I tend to be a fairly neutral (not much over- or under- pronation) and relatively mid foot striker.   Could I be better - of course! - but heel striking isn't the fundamental cause of my plodding.   So what else is there?

I think that it basically comes down to technique and mechanics.  The Pupetter has told me many times that my running is "stiff" or that I "run like a plank" and I have been doing a lot of rotational stretching exercises to try to improve my "contralateral rotation" - basically have my left shoulder work better in tandem with my right leg and vice versa.  I know that I need to "toe off" more and, in particular, to "finish" each stride.  I also need a slightly higher leg lift on the fore stride.  Basically this all adds-up (in my mind at least) to a more fluid "circular" leg rotation.  That's all great in theory, but trust me, it's a lot to think about and I have found it very difficult to put into practice.  Now that I'm in the off-season, however, and not particularly worried about distance or time, I'm going to try to focus every run session on technique and incorporate as many drills as I can think of - high steps; strides; cross-overs; butt kicks etc into every session.  Hopefully the strength and, in particular, flexibility work that I am doing will also help.

The two primary reasons for doing all of this of course are to avoid injury and, in particular, to get faster.  My enthusiasm for the off-season mission was brought home to me when I started thinking about running the Outer Banks Half Marathon (which I didn't end up actually running because of illness).  I think that for the first time it really dawned on me that run speed is a pretty simple combination of stride length and cadence (number of strides per minute).  It's really a pretty simple equation - if you take more strides of the same length in a given time, you will travel further.   Equally, if you take the same number of strides in a given time, but each one is longer, you will also travel further.  If you can take more strides and each one is also longer, you will travel even further! (gee get this guy on the phone!)

"That Roger guy is a freakin'genius!"
Now clearly, trying to achieve the stride length of Wilt Chamberlain over night while running like Roadrunner is a recipe for injury and disaster....
I must increase my cadence!
....but just for fun I started to do some simple arithmatic based around a half marathon.   I'm a bit faster than this, but let's say for the sake of arguement that with my current technique I run a half marathon in two hours. 

How many strides do I take?   Well, I have no idea, and it obviously depends on my leg length, technique, flexibility, muscle mass and various other factors.   I'm 6 ft tall and, as noted above, I'm a plodder, so I'm going to assume that I take more total strides than "good" runners.   A quick internet search gave quite a variety of answers for number of strides in a full 26.2 mile marathon, ranging from 41,280 to 55,334.  For a half marathon-specific search I quickly found 26,218 and 30,240.   Given my plodding and for simplicity's sake, let's call it 30,000 strides in a half marathon.  

There are 63,360 inches in a mile, so in a 13.1 mile half marathon there are 830,016 inches.

If I were to take 30,000 strides, that would make my stride length approx. 830,000/30,000 = 27.66 inches.   I do not have a remote idea if this is correct, but it seemed at first to "pass the sniff test".   A quick look at the Livestrong website gives a formula for determining approx. stride length (in men) as height in inches multiplied by 0.415   I am 72" tall, and 72 x 0.415 gives an approximate stride length of 29.88 inches....    but that's a walking stride length.   

Given that we are talking about a half marathon being run towards the end by a tired old fat guy, we'll take the 27.66 inches as our approximation for this exercise.

What about cadence?   This I have a better idea of, as The Puppeteer has had me measure this many times during workouts.  In general, my cadence isn't too bad.  When I concentrate over shorter distances I can relatively easily maintain a cadence of 88 to 90 "right foot plants" in a minute, but we're talking about a half marathon here, so let's re-assess and sanity check:

A 2 hour (120 minute) half marathon requiring 30,000 strides would require 30,000/120 = 250 strides per minute.   We must remember that cadence is the number of "left right cycles" i.e. count every right foot strike or every left foot strike, not every foot strike) so we must divide by two.....   125?  No, somethings clearly wrong here.

Pretty sure that it's that damned stride length.....

OK, so let's put down a slightly more "real" half marathon time of 01:55 (115 minutes) and look at it another way.....   if I maintain a "real" run cadence of 80 per minute for 115 minutes, over 830,000 inches - what's my stride length?   

80 x 2 strides per cycle x 115 minutes =  18,400 strides.       830,000/18,400 = 45.1 inches

So the stide length divided by the square root of the hypotenuse......

Damn, my head is going to explode!   Could I really have a 45 plus inch stride length?    The simple answer, it turns out, is yes.   Sprinters have a stride length of well over 6 feet, so a "plodding" stride length of 45.1 inches over a long distance isn't that unrealistic.  Certainly good enough for this exercise!

So, what the heck is the point of all of this I hear you ask?  It's quite simple really, I was quite interested to see what even small changes to my stride length or cadence would do to my "theoretical" half marathon time and use it as motivation to work on flexibility, core strength and run technique (in my book, all three have to be there before I can speed up!)

Being the data geek that I am I whipped-up a simple Microsoft Excel formula and soon had this 3D surface graph plotted to show the relationship between stride length and run cadence on my theoretical (and I stress, theoretical!) half marathon time...
I have to say that the results are pretty stunning and provide a great deal of motivation for me to improve my run technique!

First thing to say is that it would not be sensible to deliberately try to "force" a longer stride - in fact it would almost certainly be counter productive, but it's interesting to see that if improved toe-off, finish and flexibility gave me an increased stride length that was increased by just one inch (that's about 0.5%) then if I maintained the same cadence my theoretical half marathon time would drop from 01:55:15 to 01:52:45.

Where it gets really interesting (and achievable!) is when you look at what happens if you keep the same stride length and increase cadence.   Increasing cadence from 80 to 85 takes you from 01:55:15 to 01:48:30.   If you run all 13.1 miles at a cadence of 90 while maintaining stride length, you would run a theoretical 01:42:30!

So what's realistic for me?  I certainly think that with training and effort I could maintain a cadence of 85 and get that 0.5% increase in stride length.   That combination would have my theoretical finish time at around 01:46 - a pretty impressive improvement!   If there happened to be a 1% increase in stride length (it doesn't sound like a lot, does it? roughly two and a half more theoretical minutes would dissolve from the clock.  I am stoked by this!   Looking at things this way (for me at least) makes a 01:45 half marathon seem much more like an achievable goal.  It will take a lot of work, and no one said that it would be easy or that there is a "magic cure for plodding", but somehow I can visualise it!

Now what happens if I loose another 10 lbs?..........
OK, I'll save that for another post!

Maybe I won't have to become an honorary member after all!

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