CYCLICAL NATURE OF RUNNING CALCULATORS

*Nothing I say here (or ever) constitutes professional advice, just personal experience and some experience-based questions.

It may seem ironic for me to start a post that is critical of running calculators by saying that I LOVE THEM. That's not to say that they are for everybody (nothing is), but I find them to be a very helpful training tool. One of my favorites is the McMillan calculator...and I mean that. 

The McMillan calculator is one of the biggest tools in my arsenal that I use to coach myself as a runner. What could be better? You just pop in one of your most recent race times, hit the button and out pops a full list of your ideal race paces for any practical distance, and training paces. It's great.

This does not mean that I am oblivious to the criticism of the McMillan running calculator and other similar calculators. 

For example, a few years ago, I could have popped my "magic mile" time of 6:10 into the calculator and up would have come a bunch of paces: 

I should run a 5K at 21:24 (that was pretty accurate)

A 10K at 44:27 (a little less accurate)

A Half Marathon at 1:39:06 (no way in Gehenna! Not happening!)

And a Marathon at 3:28:34 (not a prayer! The odds of rainbow-colored unicorn sipping a latte running across my path during the run are higher!) 

So the criticism with the McMillan running calculator is that it gives paces that are too aggressive the longer the distance is! The rebuttal is that the times given are not what you could run right now, but reflect your potential to train up to that pace at the longer distances. So, if you are a 6:10 miler, you have roughly 3.5 hr marathon potential. I agree with that. That's why I like calculators like the McMillan because I take them for what they are. They acknowledge that you need to train up for a given distance in order for the time to be most accurate. They also know that everyone is different and that some 6:10 milers will NEVER run less than a 4 hour marathon, and some 3 hour marathoners may not be able to drop a 6:10 mile very easily. So, potentially, some 6:10 milers will NEVER hit the 1 hr 39 minute half marathon time and some 1 hour 39 minute half marathon runners will never hit the 6:10 mile mark. 

The first kind of runner has more genetic potential for speed over short distances, and the second runner is more adept at endurance than short bursts of speed. Fast twitch, slow twitch, fast twitch I and II and Ia, b, c and IIa, b, c, neurological adaptation, blah...blah...blah {insert some scientific studies if you want here...They're not really my point in this whole post anyway...}!

So, I acknowledge that, and I acknowledge that, depending on a bunch of science that we will not delve into here, some runners may be better adapted to speed at short distances vs. endurance or whatever...

Moving on...It dawned on me one day that there is still something of a conundrum about running pace calculators!

The conundrum is this: Improvement at one kind of race often leads to improvement in others.

So that sounds obvious, but stay with me and you will see what I mean. Again, this is nothing to do with science or expertise of any kind, just personal experience.

So let's say in my first year of running I am a 6:10 miler. Entering this time into the calculator, I get a projected half marathon time of 1 hour 39 minutes and change. Let's say that there is no way I am even able to run 13.1 miles at that point and even if I run as far as I can and walk when I can't run anymore, I am looking at maybe a 2.5 hour time.

The 1 hour 39 minute time isn't about this though--it is about my POTENTIAL. So, I happen to agree and decide to train up for the 1 hour and 39 minute time. What does this involve? Working up to maybe 6 x 800 intervals once a week, a 2 hour long run, 50-60 minute tempo runs and some easy runs.

Now take a straw poll: "If you do 6 x 800 intervals at a 7:00 pace once a week, a 2 hour long run once a week, and an hour of tempo work at around 7:45 pace, what will happen to your mile time?"

BINGO! You see where I am headed, right. Doing Half Marathon training to hit your "potential" is going to improve your fitness at the mile.

Finish playing out the analogy though for the sake of fairness. I wake up one day and drop a Half Marathon in a time of 1 hour and 39 minutes. So, I have hit my potential, right? In terms of the original McMillan running calculator (or whatever running calculator), yes. The projected potential was attained.

There is a problem with the running calculator prediction though!

What is the problem? The 6:10 miler should run a 1:39:00 half marathon according to the calculator and that is what happened. So where is the problem? The problem is the improved mile fitness. Go run a mile again with fresh legs after all that half marathon training and see what happens. Maybe the 6:10 miler now runs the mile in 5:30 as a result of all that "half marathon training!" So that runner goes back to the drawing board and puts in the revised mile time of 5:30...

Here are the new running calculator times:

A 5K at 19:05 now instead of 21:24 

A 10K at 39:39 instead of the former time of 44:27 

AND HERE'S THE KICKER--A Half Marathon at 1:28:23 instead of 1:39:06 

SO IT WAS ALL FARCE! I DIDN'T REALLY HIT MY RUNNING-CALCULATOR-PREDICTED HALF MARATHON TIME! It only looked like I hit my "potential" because I was using an outdated mile time! I really had the potential to hit 1:28:23!

MC Escher's Drawing Hands

So you see the problem? Running calculators are cyclical. They are like the song that gets on everybody's nerves or an M.C. Escher painting! 

 Running calculators basically set up an impossible situation in which satisfying one end of your potential (speed--the mile) can alter the projection at the other end (endurance--half marathon).

Now here is where I issue a huge note of caution!

The conundrum is not necessarily a bad thing. Otherwise it is like saying that as a runner you hate improvement. Isn't that why a lot of us like these calculators in the first place? To try to improve? I don't see any problem with the cyclical nature of running calculators other than to be aware that it happens.

For me, I started around the 6:10 mile, and got my training paces off of that time. Eventually, the mile time dropped which changed my training paces. I am learning to simply become diligent about running the "magic mile" every once in a while just to make sure my training paces are on par. (I recently wrote a post about my tempo pace being too low for too long because I had slowly gotten faster without realizing it and kept running tempos at the outdated, too slow pace!)

For me, the step-back week is a great time to run a magic mile and update your training paces (or at least make sure they are on track).

Recently, I have lived the "hypothetical" example I have outlined here. I based my training paces off of the McMillan calculator and worked to hit the half marathon time it suggests. In the course of my half marathon training, my mile time improved.

The result is that just as I was getting close to hitting the half marathon pace suggested by the running calculator my mile time improved, causing the running calculator to give me a faster suggested half marathon time.

So you can see from my experience that training for the half marathon pace improved my mile time which suggests I should be aiming for a faster half marathon pace.

The problem is: How can I ever know the right training paces if it is so cyclical?! The benefit is: Who cares?! It is a great problem to have because it means I am still improving! That is a problem that most people can envy, so if it happens to you, just enjoy it. 

At some point, most runners hit a plateau and would stop seeing this cycle with running calculators. But that becomes the subject of a much different post for another time!

What is your experience? Post in the comments below to help out other runners! Do you have any luck with running calculators? Love 'em? Hate 'em?