Introducing Running Writings Lab, my scientific pace calculator app for iPhone and iPad

I’m happy to announce the launch of Running Writings Lab: my new iPhone and iPad app featuring all of my scientific pace calculators, rebuilt from the ground up with iOS-native features. These new features include: 

  • Real-time weather conditions for heat and wind-adjusted pace calculations
  • Haptic input dials with a physical “click” for inputting paces and times
  • A home screen where you can pin your favorite calculators
  • Compatibility with both iPhone and iPad
  • Calculations that happen fully offline (no data connection needed!)

Many of you have asked for an app version of my pace calculators so I’m thrilled to finally launch it!

RW Lab is a one-time $9.99 USD purchase. Then it’s yours forever—no recurring subscription, and no ads or tracking either. Plus, once you have the app, any new calculators I develop (like my new altitude calculator) will get added automatically as free updates to the app.

My web calculators are still free, as always. The RW Lab app makes it easier to quickly calculate paces on your phone or tablet, plus add functionality (like local weather) that is only possible with an app. Every purchase helps fund my ongoing research to develop new and better tools for training.

Download RW Lab on the App Store at the link below:

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New altitude-adjusted pace calculator

I just released a new web app for calculating altitude-adjusted pace! If you live at altitude and are traveling to sea level, or vice versa, it’s a super helpful tool for training and racing. 

🏔️ Try my new altitude-adjusted pace calculator here!

Unlike other altitude calculators, my new altitude-adjusted pace app can explicitly account for what altitude you live and train at. So, if you live at 6,000 feet, run a 5k at 5,000 feet, and want to know what you could have run at sea level, my new web app will tell you! 

The key insight behind this calculator is treating every race at a different altitude as a “natural experiment” – after factoring out the effects of things like wind, weather, and terrain, the statistical model that powers the calculator estimates the independent effect of the altitude of the race, then applies a “discount” based on what altitude the athlete lives and trains at. 

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Elite marathon training with Victor Urquhart Smångs

I just recorded a great podcast with Victor Urquhart Smångs, a coach and 28:57 10k runner in Sweden who is in the middle of a big build-up for the Valencia Marathon. We talked about elite-level marathon training, including key workouts, periodization, and heat versus altitude training. 

Check out the full episode on your podcast app of choice: 

🎙️ Listen on Spotify here

🎧 Listen on Apple Podcasts here

To follow Victor's training, check out his Instagram here, and check out the rest of his podcast episodes on Runners FM. As always, if you enjoy the show leave a review and share the episode with your friends and training partners!

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Talking marathon training on the Life in Stride Podcast

I just went on the Life in Stride Podcast to chat about all aspects of marathon training—workouts, periodization, fueling, tapering, recovery, and more! 

This was a super fun chat with Chris, Scotty, and Danny, and it was great to get their own perspectives on training (Chris had just done the classic 8 x (1k, 1k) workout that morning) so definitely give it a listen! Check out the episode on your favorite platform here: 

🎙️ Listen on Spotify

🎧 Listen on Apple Podcasts 

🖥️ Watch on YouTube

You can follow the Life in Stride Podcast here on Instagram, or here on YouTube. Remember to like, review, and share the episode with your friends and training partners if you enjoy it—it’s a huge help to creators like Chris, Scotty, and Danny!

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New web app: Predicting LT1 pace and Zone 2 pace from 5k time

I’m excited to launch a new app for predicting training paces: my LT1 and Zone 2 pace calculator is now live, and provides a simple and accurate way to estimate your first lactate threshold, or LT1 pace, as well as an upper limit for your easy run pace, a.k.a. Zone 2 pace. 

📲 Check out my LT1 / Zone 2 app here! 

Normally, LT1 requires a standardized blood lactate test for reliable results. But with this app, all you need is your 5k time (or a reasonable estimate of your current 5k fitness).

Under the hood, this calculator relies on real scientific data from thousands of runners and state-of-the-art statistical techniques to come up with its estimates. 

Try out the calculator at the link above, or read on if you want more details on the science behind how it works.

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New horizons in iliotibial band biomechanics in runners

The iliotibial band, or IT band, is a thick strip of fibrous tissue on the outside of your thigh. It’s the fifth most common location of injury among runners, and it’s also a very weird anatomical structure.

Two completely different muscles, with seemingly different roles during running, both connect to the IT band: 100% of the fibers of the tensor fascia lata, on the side of your hip, connect to the IT band, but so do about 50% of the fibers of the gluteus maximus (one of the prime movers of the hip joint).

Another strange thing about the IT band is that it seems to be a uniquely human structure: chimpanzees and other primates do not have an IT band (almost all of their gluteus maximus fibers connect directly to the femur, and their TFL muscle inserts on a shorter fascia that terminates above the knee).

Despite its anatomical uniqueness, and its high rate of injury, we—meaning the biomechanical and sports medicine community—don’t really understand a whole lot about what the IT band is doing during running (or walking or cycling, for that matter). All of the most popular “musculoskeletal models” of the body used for gait analysis don’t have a true IT band: they just have a TFL that goes down the side of the leg, and a gluteus maximus that inserts along the femur.

I have just published a new preprint that addresses this problem. The title tells it all: “A full-body musculoskeletal model with an anatomically informed iliotibial band.”

You can read the full preprint below, if you want the technical details, or read on for some highlights on how this model of the IT band works and I think it will be very useful for studying IT band mechanics during running.

📄 Read the full paper here

Something to understand: this paper is a beginning, not the end, for my research on IT band biomechanics. The big centerpiece—simulating five gait cycles of running at 8:30/mi pace for one runner—won’t blow you away, though it is a big technical accomplishment, and it  does produce some nice visualizations. This study, and this IT band model, are a foundation for future research (some of which I’m working on already) into many different aspects of IT band biomechanics.

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Designing a plyometrics program for improving bone strength in young runners

Stress fractures are an incredibly frustrating injury, especially for young runners. Even though the science behind recovery from stress fractures—more properly called “bone stress injuries”—has advanced significantly in the last several years, sustaining a bone stress injury can still completely derail your season.

Of course, far better than a swift rehabilitation is simply not getting a stress fracture in the first place (or at the very least, avoiding another one). That’s what we’re concerned with today.

Thanks to advances in the fundamental science of bone injuries, we now know that a powerful lever at your disposal for increasing your resistance to bone injuries is improving your bone strength. The best way to do that? Targeted plyometric training, a.k.a. “jump training.”

This kind of high-load, high-loading-rate intervention is especially effective at improving bone strength in young runners—roughly, teens and pre-teens, with some wiggle room on either side for individual differences in puberty and growth spurts.

However, if your goal is building bone strength, you should not use a general-purpose, performance-oriented plyometrics program for runners. Plyo programs that target bone strength need markedly different components for maximum efficacy.

Below, I’ll walk you through the science behind building a plyometrics program for bone strength, including total contacts, types of jumps to include, and appropriate programming during the week.

If you just want to get the final plyo program as a printable PDF, you can download it here: 

📋 Download the bone strength plyometrics program here

Otherwise, read on to learn the science and practical programming behind this plyo routine!

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Three theories of tissue damage accumulation during running

Suppose you need to run 15 miles (24 km) in the next week. You can distribute this volume however you want, both within and across days. Your goal is to cover the requisite distance in a way that minimizes your risk of injury. Does it matter how you schedule out your week?

This is one concrete way of thinking about the question of cumulative damage in running: given that you’re going to cover some combination of distances and speeds, does the ordering affect how much tissue damage you’ll accumulate?

We’ll look at three different theories on how tissue damage accumulated during training. These aren’t exactly competing theories—more than one can be correct—but considering each framework separately helps sharpen up how you think about programming your training.

I think all three have some truth to them, though I’m still skeptical of the strongest version of each of the three (and I’ll explain why).

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Podcast: Marathon Excellence on Running Book Reviews with Alan and Liz

I was just on the perfectly-named Running Book Reviews Podcast to chat with hosts Alan and Liz about my book, Marathon Excellence for Everyone.

We talk about why I wrote the book, how I approach periodization for the marathon, and how to mentally approach race day, among many other topics.

I really enjoyed this show because Alan and Liz have a huge amount of knowledge about the various ways different coaches approach the marathon and it really shows in the podcast. 

Check out the show on your favorite platforms below! 

🎙️ Listen on Spotify

🎧 Apple podcasts

🖥️ Watch on Youtube

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What can Garmin RunDynamics and Stryd data tell you about biomechanical training load?

I just published a new scientific study—this paper was basically the centerpiece of my PhD dissertation, and the title more or less gives away the premise: “Predicting Achilles tendon and patellofemoral joint forces during running with consumer-grade wearable sensor data.”

In this study, “consumer-grade wearable sensor data” means RunDynamics from a chest-worn Garmin heart rate monitor and similar data from a Stryd foot pod. If you aren’t familiar with these devices, they use on-board sensors to estimate biomechanical parameters like your cadence / stride length, vertical oscillation, ground contact time, and so on.[1]

There are a few issues with the gait metrics you get from these kinds of devices, though. First, are they accurate? And second…do they actually tell you anything about what’s going on inside your body?

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Check out my new book on marathon training!