In this episode of the Female Athlete Nutrition, I talk with a returning guest, Dr Nicky Keay, world-renowned sports endocrinologist specializing in female athletes. Tune in to Episodes 38 and 98 for my previous conversations with Dr Nicky Keay. For the first time in 129 episodes, we dive deep into all things thyroid and the hormones it produces. Don’t worry, Dr Nicky does a great job at explaining the science in a way everyone can understand! We debunk myths around metabolism, metabolic rate and body composition, and how the thyroid is involved. Dr Nicky and I discuss how thyroid hormones are regulated and what happens when that goes wrong. We cover conditions of the thyroid gland, hyperthyroidism and hypothyroidism, signs, symptoms, and treatments. Dr Nicky talks about the place for thyroid medications and the caution they need to be considered with. We explore the impact of RED-S on the thyroid gland and its hormones, how being in a state of RED-S can suppress hormone production, and widespread effects of this like missing menstrual cycles. The good news is that RED-S recovery is the most effective way for healing the thyroid and its hormones, not medication! Dr Nicky has a great book exploring this and much more, check it out: Hormones, Health and Human Potential. Hear more from Dr Nicky on Episode 38 and Episode 98 of the Female Athlete Nutrition podcast  Follow Dr Nicky and her work on Instagram and Twitter @drnickykeay and her website https://nickykeayfitness.com  Follow me, your host Lindsey Cortes, on Instagram @female.athlete.nutrition  We have a huge announcement! We are launching patreon! Female Athlete Nutrition podcast patreon is now LIVE and we are excited to offer our community unique perks. Join today and receive bonus episodes, merch, monthly recipes, access to an exclusive community message board, and have the chance to ask Lindsey your questions and get a podcast shoutout, and more! Head to patreon today patreon.com/femaleathletenutrition  Need help with your fueling? Want to get in touch with Lindsey? Interested in the Female Athlete System of Transformation?  Head to www.RiseUpNutritionRUN.com to learn more & book a call! THANK YOU TO OUR SPONSORS: Previnex: https://www.previnex.com/ use code RISEUP for 15% off at checkout InsideTracker: www.insidetracker.com/riseup for 20% off the entire store for a limited time only! THIS PODCAST IS ALSO SUPPORTED BY: Orgain, head to www.orgain.com and use the code RISEUP30 for 30% off your first order. Repeat customers can use the code OA2203 for 25% off future orders. Practice Better Click the link below to view plans and get a 14-day free trial. Then use the code RISEUP20 for 20% off your first 4 months: https://practicebetter.grsm.io/runp  Jen & Keri: https://jenandkeri.com/ use code RISEUP10 for $10 off your order In this episode we talk about: 3:30 What are the thyroid hormones and what their functions 7:00 How our body regulates hormones 8:15 Understanding metabolic rate and weight changes 14:30 Exercise for improving your metabolism  19:00 Defining resting and basal metabolic rates 21:20 Hypothyroidism vs hyperthyroidism  22:20 Hyperthyroidism: overactive thyroid gland; Graves disease 28:00 Hypothyroidism: underactive thyroid gland; Hashimoto’s disease  31:45 For and against thyroid medications 37:30 The impact of RED-S on the thyroid hormones 42:30 Healing the thyroid during RED-S recovery 48:00 Autoimmune diseases and thyroid problems co-occurring with RED-S 50:55 Learn more about Dr Nicky Keay and her work