Your Training Isn’t Broken—Your Fueling Is: RD Cortney Berling on Solving RED-S and Getting Faster

Most runners think their biggest limiter is training volume, paces, or genetics. Cortney Berling says it’s something much simpler: you’re not eating enough.Fresh off a 2:52:49 finish at the 2025 Eugene Marathon and armed with her credentials as a Registered Dietitian (MPH, RD, CDE), Cortney sits down to unpack RED-S (Relative Energy Deficiency in Sport): what it is, why it matters, and how to fix it before it derails your running and your health.Cortney’s perspective is unique because she’s lived it on every stage: from a 3,000m steeplechase PR of 11:05.95 at the University of Cincinnati, to a 1:22 half marathon in Portland (2024), to road wins like the Old Port Half in Maine (2017), to her current life as a sub-3 marathoner in Oregon. Along the way she’s been a board member and elite athlete coordinator with WMDP, coached high school runners, and led community seminars with OHSU Sports Medicine.She knows firsthand how under-fueling can lead to injuries, stalled progress, and experienced fertility challenges linked to under-fueling in her own journey — and how the right fueling strategy can flip the script.If you’ve ever bonked, felt flat despite training hard, or struggled to balance nutrition with performance, this episode is your wake-up call. Tap into the Cortney Berling Special.  If you enjoy the podcast, please consider following us on Spotify and Apple Podcasts and giving us a five-star review! I would also appreciate it if you share it with your friend who you think will benefit from it. Comment the word “PODCAST” below and I’ll DM you a link to listen. If this episode blesses you, please share it with a friend!S H O W  N O T E S-The Run Down By The Running Effect (our new newsletter!): https://tinyurl.com/mr36s9rs-BUY MERCH BEFORE IT’S GONE: https://shop.therunningeffect.run-Our Website: https://therunningeffect.run -THE PODCAST ON YOUTUBE: https://www.youtube.com/channel/UClLcLIDAqmJBTHeyWJx_wFQ-My Instagram: ⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠https://www.instagram.com/therunningeffect/?hl=en⁠⁠⁠⁠⁠⁠-Take our podcast survey: https://tinyurl.com/3ua62ffz