From: "Mikael Eriksson" <firstname.lastname@example.org>
Date: May 20, 2017 12:31 AM
Subject: How to adapt your running pace on hills and in headwinds (real numbers!)
I recently came across some very interesting findings that I wanted to share with you:
How running uphill and into headwinds affects the energy cost of running (ECOR). And more importantly, what does that mean for running pace.
What is the ideal pace change when some nasty race director puts a hill or a headwind in your way?
The data I'm about to share comes from white papers (here and here) published by Hans van Dijk and Ron van Megen. Hans is a scientist and retired professor from the Delft University of Technology and Ron is an engineer.
The pair has authored the book "The Secret of Running" which I just ordered and can't wait to sink my teeth into.
- The (theoretical) energy cost of running increases by 4.5% per percent grade of the hill your running up.
- This means that if your pace on flat ground is 5:00 / km (8 minute mile pace), and you come to a 3% hill (which isn't steep at all), your pace should become 5:41 / km (9:08 mile-pace). The math is (1 + 0.045 x 3) x 300 s/km = 341 s/km = 5:41 / km.
- Hans and Ron tested the theoretical model in practice (see the white paper). They used the Stryd running power meter and could confirm these results.
Running into headwinds
- With wind the theoretical model gets much more complicated. The energy cost of running increases as the square of your running velocity plus the wind velocity. And what's more, the power required to overcome air resistance itself changes. See the white paper for more details.
- But as a practical application example, say you're running at 3:58 pace (6:23 mile-pace) in still conditions. And then you turn into a 15 km/h headwind (~9 mph). Your pace now should become 4:24 (or 7:04 mile pace). If you turn into a tailwind, you can increase your pace to 3:48 (6:06 pace) at the same energy cost of running (and same power).
- Again, Hans and Ron tested this in practice. In this case though, we need more testing to verify how accurate the model is. At the moment, running power meters don't take winds into account when calculating running power. At least Stryd doesn't, but they're working on it.
My guess is that although you decrease your running pace on hills and in headwinds, the changes you make are not this dramatic. I know that's the case for me at least. (Which is one of the reasons why I finally caved and ordered a Stryd unit for myself...)
My challenge to you is to try and think about these things on your next run. Slow down properly on hills and in headwinds. Try it out for size and see how it feels. Does it affect the overall quality of your run?
Now over to you, let me know how it goes!
Have you been staying on top of recent podcast episodes? Since my last email, the new episodes that have been released are listed below. You can listen to them or just read the shownotes here.
- Open water swimming: training and racing tips with coach Brenton Ford | EP#18
- Improve your triathlon running and give duathlons a go with Eric Schwartz | EP#19
- Masters Athletes: How to minimize performance declines for the aging triathlete | EP#20
- Mission "Grow Triathlon" with USAT president Barry Siff | EP#21
- Performance nutrition for triathletes with Steph Saullo | EP#22
- Run like sub-4 minute miler and pro triathlete Sean Jefferson | EP#23
And this coming week we have a couple of really great episodes coming out (aerodynamics and free speed on the bike with Nuno Prazeres, high-performance
coaching with elite coach and USAT coach of the year 2016 Paulo Sousa), so do subscribe to the podcast on iTunes or your favorite podcast player app (I recommend Pocket Casts for Android users).