Bridging the GAP.

The 7^th of April, 2015 AD.

Late evening.

My first run in the mountains where I now live.

I remember standing outside my room, in a gracefully contemplative pose, waiting for my Garmin to lock on. The goal was to run an out-and-back, tempo-effort 10k. This was undoubtedly the hilliest terrain I had ever run on. I was not really sure what was about to happen, and there was only one way to find out...

Long story short... an hour later, I was in a different pose... on my knees at the exact same spot, gasping for breath, leg muscles aflame, whimpering like a Grade-A wuss.

Over those 10 kilometers, I had climbed almost 500 meters.

Hills do strange things to runners....things that are almost impossible to accurately calculate, and therefore, compensate for.

Consider this...

An ‘out-and-back’ run is one on which you run to a point and then return along the same route. On such a route, you invariably climb exactly as much as you descend, irrespective of the elevation profile. Since you run slower than average on uphills and faster than average on downhills, intuitively, the effects of the two should cancel out and one should be able to run, on average, as fast as one would run the same distance on flat ground.

But, as any moderately experienced runner will tell you, that doesn’t happen...

You never gain on downhills, the time you lose on uphills. The factor here is approximately 0.5, i.e. while running downhill, one tends to make up only half the time one has lost running up the hill.

Since I am about as mathematically skilled as the average kitten, I saw that this was really going to be a problem when I started training in earnest for Dubai 2016. Training by pace (which, on flat ground, is proportional to effort) is all I knew.

The obvious alternative was to train directly by effort, or heart-rate zones, something that almost all wise runners and coaches advocate anyway.

I don’t have a heart-rate monitor. So much for that, then.

Another step up the wisdom ladder, people swear upon training by feel.

Somehow, even that didn’t seem to work (at least for me) on the kind of ups and downs I was facing.  Going by feel, I realized that running up or down a slope at a variety of paces felt equally hard/easy.

With no reliable numbers to help me, I was doomed to train by faith... something that, as on date, I continue to do.

Not entirely, though.

A couple of weeks and a few more disastrous runs after that first disastrous run, I ported my runs to Strava.

And there, under the pace/elevation graph, I saw this little thing...

...and I was like, “Whoa!”

Quoting Straight from Strava’s knowledge-base... “Grade Adjusted Pace estimates an equivalent pace when running on flat land.”

It sounded exactly like what I needed, right? Yet, I remained wary...

Firstly, GAP is an estimate. It’s a re-evaluation of my actual data by some mysterious algorithm living in Strava’s servers. It's not real.

Secondly, the algorithm is based on a study. Quoting again, “...work done by C.T.M Davies and Alberto Minetti studying the effects of grade on the energy cost of running.” Statistical studies are like tequila. A pinch of salt is essential. They work well for populations, not individuals.

While Strava's coders seem to have done their best to improve the accuracy of GAP, I just couldn't rely on it.

I looked back at that first run...

Feel- All-out best effort (~4 minutes/km)

Actual Pace (~6 minutes/km)

GAP ( ~5 minutes/km)

Well, that didn’t help at all.

Epilogue: Now.

After about seven months of running on the same terrain, I ran an 18k yesterday (climbing 1100 meters), and the picture was somewhat different.

Feel- Twilight Zone, harder than Tempo/ easier than best effort (~ 4:30 minutes/km)

Actual Pace (4:42 minutes/km)

GAP (3:36 minutes/km)

Three-bloody-thirty-six!

Four weeks to the incline-less ADHM, I see that I’m touching GAPs that, if accurate, should see me crossing the finish line in about 75-77 minutes! 

Is that even possible? Dare I be that ambitious with my goal? Let me meditate on that.

One way or another, ADHM is sure to give me some sort of indication about how seriously I should take the whole GAP business. Right now, surrounded by hills, I have no way of knowing.

In any case, before I taper into that race, there are three monstrous weeks to go with my weekly mileage slated to peak at 112 km. Here’s a picture of the last month, if you’re interested...