The Nutrition Mistake Secretly Destroying Performance In Runners Over 40

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.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.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.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.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.➡️ Join The Endurance Lab Inner Circle on Telegram👉 https://t.me/TheEnduranceLabInnerCircle🔥 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.➡️ Endurance Lab listeners SAVE $100 OFF the Tymewear Pro Training membership Code: E-LABTW26👉 https://www.tymewear.com/E-LABTW26➡️ Listen to my conversation with TimeWear founder Anar Larson: 👉 https://youtu.be/tNybWS7uae0➡️ Rebecca’s Website:👉 https://beccamcconville.com➡️ Rebecca’s book: Finding Your Sweet Spot: How to Avoid RED-S and Fuel Your Athletic Performance👉 https://www.amazon.com/dp/1091089051?lv=shuf&channelId=500&plpRedirect=mhFallbackChapters00:00 The hidden problem affecting masters athletes02:30 What is low energy availability and RED-S?04:54 Why calories are not the whole story06:44 Are older athletes at risk of RED-S?08:26 How athletes accidentally fall into underfueling11:10 The long-term health consequences of chronic underfueling13:11 Why aging can hide RED-S symptoms14:20 Early warning signs you should not ignore17:35 Digestion, sleep, immunity and RED-S symptoms18:49 Can HRV and resting heart rate reveal underfueling?20:46 Can you have low energy availability without symptoms?21:52 Is fasted training actually beneficial?23:28 Fat oxidation vs endurance performance26:58 Keto diets, carbohydrates and RED-S risk31:33 Losing body fat without destroying performance35:03 How much energy do endurance athletes actually need?36:27 How to recover from RED-S39:07 Why carbohydrates matter during recovery40:30 How long does RED-S recovery take?44:37 Can you keep training while recovering from RED-S?47:44 Finding help and working with RED-S specialists50:41 The biggest nutrition mistake masters athletes make51:35 The one nutrition change athletes should make today52:24 What does endurance mean to Rebecca McConville?