This article is more beginner-focused, of course, but I’ve always enjoyed how the same basic insights about training, adaptation, and improvement apply to people who are exercising for fitness and health as well as people training for serious competition.
If you want to learn more about the science of running I have a ton of related articles below, with more in the works for 2026. If you want to find out when I have new articles, web apps, or podcasts coming out, subscribe to my email newsletter below! It’s the best way to stay up to date with my work.
I also have two books out: Modern Training and Physiology, a short guide on scientific training for 800m to 10k, which I published in 2013, and my brand-new book Marathon Excellence for Everyone, which covers the modern, scientific way to train for the marathon. Check them both out!
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 ... Read more
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 ... Read more
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 ... Read more
I just posted the video from my live lecture on the science of modern marathon training! In the video, I uncover the science behind the modern approach to marathon training, including how VO2max, running economy, lactate threshold, and physiological resilience each contribute to marathon performance. Then, I explore the training methods that most effectively target ... Read more
After launching my power law calculator earlier this week I got a couple emails from readers who noticed some counter-intuitive behavior. Suppose you have an athlete who has run 800m in 2:25 and 1600m in 5:10. The power law calculator predicts a 3200m performance of 11:03—pretty reasonable. Then suppose your athlete improves their 800m time ... Read more
Very often, in training discussions online and in books—even sports science textbooks—you encounter the claim that, during running, tendons stretch out and store up energy on impact with the ground, releasing that energy later when you push off the ground. This energy storage improves your running economy, because without it, you’d have to produce that ... Read more
Suppose you are running a 5k race on an out-and-back course, and there’s a strong headwind on the way out—should you aim to run at the same effort the whole way, allowing the wind to slow you down on the way out and speed you up on the way back? Or should you maintain the ... Read more
Your cadence is the number of steps you take per minute while running. Simple measurement, right? But there are many questions surrounding it, including how it differs across runners, how it changes as you run faster, whether a higher cadence is more efficient, whether a lower cadence causes injury, and whether you should aim for ... Read more
In my article on biomechanical training load, I covered the basics behind how biomechanical loading is related to the development of running injuries. The basic idea is pretty straightforward: every time you take a step, your tendons, bones, and joints experience a loading cycle: a build-up and release of mechanical force. Each loading cycle does ... Read more
What do we mean when we say “training load”? This is the second article in a three-part series aimed at answering that question. My core argument in this series is that there are three distinct types of training load you should consider—physiological training load, biomechanical training load, and psychological training load. Today, we turn our ... Read more
About the Author
John J. Davis, Ph.D.
I have been coaching runners and writing about training and injuries for over 12 years. I've helped complete novices, NXN-qualifying high schoolers, elite-field competitors at major marathons, and runners everywhere in between. I have a Ph.D. in Human Performance, and I do scientific research focused on the biomechanics of overuse injuries in runners. My new book on marathon training, Marathon Excellence for Everyone, is now available on Amazon!
