Improve your Running Economy with Sprints on an Incline
In recent weeks, this blog has focused on the virtual trek I’ve undertaken (in the company of family and good friends!) to run the length of Great Britain, from Land’s End to John O’Groats.
But I’ve also spent part of the pandemic catching up on some of the best peer-reviewed evidence about ultramarathon training, so that when the Cameron Peak Fire subsides and I can run outside again, I’ll be able to make the best use of my limited training time.
As any athlete knows, the world is full of training information, much of it contradictory… and so it can be difficult to figure out whose advice to trust. Last year I was fortunate enough to stumble upon the “Science of Ultra” podcast, a resource provided by Shawn Bearden, Ph.D., Professor of Physiology at Idaho State University. The podcast shares the latest news from all the finest journals in the exercise physiology field and includes interviews with today’s most productive scientists.
Professor Bearden’s research focuses on bioenergetics, specifically on gas exchange kinetics (oxygen consumption and carbon dioxide production) and transitions in exercise intensity around physiologic thresholds. This area of expertise leads him to have a great perspective on how current research relates to trail running — especially ultramarathon running — because when you think about it, all trail running is essentially an extended series of transitions in exercise intensity. Uphill, downhill, negotiating technical terrain — these all affect the intensity of your effort. And how you’re able to sustain effort over a very long distance — an ultramarathon — is determined by bioenergetics. I also love that Dr. Bearden’s research covers a range of “scale” within the body, from sub-cellular signaling cascades to integrated whole-body studies of how your heart, lungs, and muscles work together during exercise.
(To sum it up, I’m a fan.)
Professor Bearden launched “The Science of Ultra” to offer runners a science-based approach to training. Back when he started to train for ultramarathons, he sought out advice about how to structure his training, and as he recounts,
When I looked for grounded, reliable, science-based content on the physiology of ultramarathon training and racing, I didn’t find much. When I did find it, the context was usually a few statements within a larger article, blog post, or podcast episode that contained a lot of other entertaining, but not actionable, information. Most important, I often heard statements that were not accurate, and sometimes misleading, with regard to exercise physiology. So, I decided to start this podcast and the scienceofultra.com website for you. I realized that I could give back to this wonderful community I had joined by providing this content, focused on the science and physiology of ultramarathon training and racing. Science of Ultra complements the many great resources surrounding our sport but uniquely delivers the reliable, valid, and actionable answers to physiology questions in ultramarathon running.
So what have I learned lately?
Professor Bearden’s most recent update focuses on a newly-published study on running economy, basically, the relationship between how much energy you expend and how fast you go. As the great running coach Jack Daniels once explained, “How much is it costing you to run 10 miles an hour? If it costs you less than it costs someone else, you are more economical.”
Strides and sprints have long been incorporated into runners’ training regimens as tried-and-true practices to improve running economy. The new study, which compared performing sprints on flat terrain to performing them on an incline, showed that the incline group had significant improvements in top running speed, stride rate (turnover) and leg strength. Those benefits weren’t surprising; a study performed a decade ago by this same research team had already shown doing sprints on an incline were helpful for performance.
But one new measure that hadn’t been tracked in the earlier study is that of the runners’ knee extensors' maximum isometric force: basically, how functionally strong and stable the knee joint and surrounding muscles are. And in this new study, runners in the up/down group improved this measure by 21% in just six weeks. This is significant because in other studies, maximal knee extensor force has been identified as a performance predictor in trail ultramarathons, and a contributor to overall running economy.
So, consider throwing some uphill and downhill sprints into your routine a couple times per week; after a few weeks you may notice your previous long-run pace starts to feel easier. And it doesn’t take much of an incline to have an effect, either: in the study, the up/down group trained on a three-degree slope (aka a 5.24% incline). That’s much less steep than many of the trails in northern Colorado.
See you on the trail!
