Sports Dietitian: The Nutrition Mistake Destroying Performance In Runners Over 40

<p>Many endurance athletes think getting leaner automatically means getting faster. But for masters runners, cyclists, and endurance athletes, there is a hidden problem that can quietly destroy performance: underfueling and low energy availability.</p><p>In this episode of The Endurance Lab, I speak with Rebecca McConville, MS, RD, LD, CSSD, CEDRD, a sports dietitian specializing in endurance nutrition, Relative Energy Deficiency in Sport (RED-S), athlete fueling, and eating disorder recovery.</p><p>Rebecca explains why RED-S is not just a problem affecting young female athletes, why masters athletes are often overlooked, and how trying to lose weight while increasing training volume can leave athletes stuck in a cycle of poor recovery, declining performance, and increased injury risk.</p><p>Rebecca shares her own experience as a masters athlete, mother, and endurance enthusiast, explaining why so many recreational athletes fall into the trap of trying to do more training while eating less.</p><p>Rebecca McConville works with athletes ranging from recreational endurance athletes to elite competitors, helping them understand the connection between nutrition, performance, health, and long-term athletic development.</p><p><br></p><p>➡️ Join The Endurance Lab Inner Circle on Telegram</p><p>👉 https://t.me/TheEnduranceLabInnerCircle</p><p><br></p><p>🔥 FIND YOUR TRUE ZONE 2 WITH TYMEWEARTymewear Vita Pro measures your breathing in real time to identify your individual physiological thresholds and help you train at the intensity you actually intend to train at.</p><p>➡️ Endurance Lab listeners SAVE $100 OFF the Tymewear Pro Training membership </p><p>Code: E-LABTW26</p><p>👉 https://www.tymewear.com/E-LABTW26</p><p>➡️ Listen to my conversation with TimeWear founder Anar Larson: </p><p>👉 https://open.spotify.com/episode/5sz25EZjGUHoGSaA38nHwM</p><p><br></p><p>➡️ Rebecca’s Website:</p><p>👉 https://beccamcconville.com</p><p><br></p><p>➡️ Rebecca’s book: Finding Your Sweet Spot: How to Avoid RED-S and Fuel Your Athletic Performance</p><p>👉 https://www.amazon.com/dp/1091089051?lv=shuf&amp;channelId=500&amp;plpRedirect=mhFallback</p><p><br></p><p>Chapters</p><p>00:00 The hidden problem affecting masters athletes</p><p>02:30 What is low energy availability and RED-S?</p><p>04:54 Why calories are not the whole story</p><p>06:44 Are older athletes at risk of RED-S?</p><p>08:26 How athletes accidentally fall into underfueling</p><p>11:10 The long-term health consequences of chronic underfueling</p><p>13:11 Why aging can hide RED-S symptoms</p><p>14:20 Early warning signs you should not ignore</p><p>17:35 Digestion, sleep, immunity and RED-S symptoms</p><p>18:49 Can HRV and resting heart rate reveal underfueling?</p><p>20:46 Can you have low energy availability without symptoms?</p><p>21:52 Is fasted training actually beneficial?</p><p>23:28 Fat oxidation vs endurance performance</p><p>26:58 Keto diets, carbohydrates and RED-S risk</p><p>31:33 Losing body fat without destroying performance</p><p>35:03 How much energy do endurance athletes actually need?</p><p>36:27 How to recover from RED-S</p><p>39:07 Why carbohydrates matter during recovery</p><p>40:30 How long does RED-S recovery take?</p><p>44:37 Can you keep training while recovering from RED-S?</p><p>47:44 Finding help and working with RED-S specialists</p><p>50:41 The biggest nutrition mistake masters athletes make</p><p>51:35 The one nutrition change athletes should make today</p><p>52:24 What does endurance mean to Rebecca McConville?</p>