Jeanne Backofen Craig

I'm a wife, mother, pianist, and runner living in Central Virginia.
You can learn more about me at wecraig.org/jeanne.
My videos can be found on my YouTube channel.

Saturday, May 13, 2017

Making the Grade

With school ending for many people at this time of year, you might think that's what this blog is about.  But it's not.  It's a continuation of my Heavy Breathing post.  HILLS!

Yesterday, I ran my hilly route again - this time I did 5 out-n-backs for a total of 8.4 miles, with 10 hill climbs.  I checked RunKeeper this morning to see my splits.  I looked at the elevation profile and wondered what % grade the hills are, as one hill is shorter & quite steep, and the other hill is longer but not as steep.

The long hill (0.5 mile) has about 150 feet of elevation change.
The short hill (0.3 mile) has about 90 feet of elevation change.

The grade of a road is the road's steepness, meaning: "rise over run."  So this means to find the % grade, you divide the elevation change by the distance.  Of course, they need to be in the same units (feet, in this case), so you have to convert the miles to feet.

There are 5280 feet in a mile.
(0.5)(5280) = 2640
(0.3)(5280) = 1584

Now to find the grade:
Long Hill:  150 divided by 2640 = 0.05681818
Short Hill:   90 divided by 1584 = 0.05681818

What???  They're exactly the same grade!!

Written as a percent, that means both of these hills have a steepness grade of 5.68%, which is a pretty decent slope.

I was shocked when I got this result.  It is EXACTLY the same... I mean, super duper unbelievably exactly the same.  I could swear the shorter hill feels harder and steeper.  Shouldn't the longer hill, of the same grade, feel harder?  Because of this, I wondered if I calculated incorrectly.  So I double- and triple-checked my math.  You are welcome to quadruple check it for me and confirm it, but I'm quite sure I'm right.

This was quite a revelation this morning and I'm not sure what it means for my future hill runs.  Either the short hill won't seem quite as difficult or the long hill will now seem longer & more difficult.  I'm hoping for the former, since I try to think positively when I exercise.

If you use a fitness app that tracks elevation, this is a fun way to see just how hard you're working in various parts of your walks, hikes, runs, or bike rides.  If you need any help with the calculations, you can always ask Google "how to calculate the grade of a hill" and find a nice description, complete with a picture.  It's just one more tool to measure our individual progress and "make the grade!"

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