Why Are Americans Getting Slower? A Look Into Running's Largest Study with Jens Jakob Andersen

We know that's a sensational title, but hear us out. A study published by RunRepeat.com, an independent review aggregator for running shoes, analyzed 34,680,750 race results over the course of 21 years to conclude that American runners are steadily getting slower across distances from the 5K up to the marathon. We know what you're probably thinking: with Olympians like Galen Rupp and Molly Huddle continually setting national records, how can that be? While it's clear US elites are steadily advancing, the study found that the remainder of the field is, on the whole, slower than it was in the 90s. Now this could be due to a variety of reasons, and some argue one of those reasons might just be that the sport has gained a lot of popularity in the last couple decades. More runners of varying age and gender? We like the sound of that. While this is certainly plausible, others argue there's another, less favorable culprit behind the trend: the rising rate of obesity in America. This is the hypothesis behind the study in question led by Danish statistician, runner, and founder of RunRepeat.com Jens Jakob Andersen. While Jens believes the correlation between slowing race times and the deteriorating health in America is too close to deny, he's quick to remind us that correlation is not causation. When it comes to statistics, Jens says it's always easier to debunk something that's not true rather than prove something that is, and that's exactly what he aims to do in this episode. Listen in and decide for yourself. Whichever way you end up leaning, you're bound to learn something interesting about yourself and your fellow runner along the way. Questions Jens is asked: 2:28 Tell us about yourself and how did you become passionate about running? 4:30 What prompted you to start RunRepeat and what does your day-to-day entail? 7:02 How is RunRepeat's Run Score calculated? 11:23 How should runners go about choosing a shoe that's really right for them? 12:32 What did you find in your study of American runners becoming slower and what do you think the implications are? 21:43 Could it be that there just aren't as many Americans in the top 1% to compensate for the greater number of people towards the back of the pack? 23:38 What would it take for Americans to reverse this trend? 27:02 Where are some of these Blue Zones located? 27:41 In your study on marathon results, what were some of the key takeaways you saw and what did the study entail? 31:58 Why do you think there has been such an increase in female runners over 50 taking up running within the last decade ? 33:38 Why do you think men tend to go out faster than they probably should when racing? 35:38 Why do you think runners ages 35-45 make the best pacers? 37:02 Based on the studies you've done, what advice would you give us on tackling our next marathon? 39:42 What's next with you at RunRepeat? Quotes by Jens: "It bothered me how 90 percent of people bought the same five pairs of running shoes, and I thought, 'Why is this happening?' It's happening because these brands...promote specific models, and so there becomes a hype around specific models." "We looked at the finisher number (number 100, number 1,000, number 2,000, number 5,000) for each race distance, and what we found was that across this all were getting slower." "It's always hard with statistics to come up with a clear cut conclusion. It's always easier to debunk something that's not the case." "Americans (as well as most other nations) are getting more and more obese, and their finish times are getting slower. But this is a correlation: two parameters that follow each other. It's not necessarily a causation….So this is our hypothesis, but we cannot conclude it for sure with 100 percent certainty." Want more awesome interviews and advice? Subscribe to our iTunes channel Mentioned in this podcast: RunRepeat.com RunRepeat Article: American Runners Have Never Been Slower (Mega Study) RunRepeat Marathon Study RunnersConnect Race Pace Calculator NPR Article: Longevity Diet Tips From the Blue Zones Follow Jens on Twitter Send Jens an email We really hope you've enjoyed this episode of Run to the Top. The best way you can show your support of the show is to share this podcast with your family and friends and share it on your Facebook, Twitter, or any other social media channel you use. If more people who know about the podcast and download the episodes, it means I can reach out to and get through to the top running influencers, to bring them on and share their advice, which hopefully makes the show even more enjoyable for you! -- Thank you to our sponsors for supporting Run to the Top Send an email to info@pacifichealthlabs.com with the subject line "Run to the Top" and ask for your FREE Accel Gel samples. Don't forget to include your address!