16. Has Your HIIT Workout Stopped Working? The Relationship Between High Intensity Exercise and Cortisol

In this episode, Sam discovers that her favorite workout routine has stopped giving her the results she’s looking for. On a journey to figure out why (and how to fix it), she explores the impact of high intensity training on cortisol levels, and how cortisol creates inflammation in the brain and body, leading to a wide range of mental and physical dysfunction. Listen to this episode if you think you’ve “plateaued” in your workouts, if you’re going hard at the gym but not making progress, or if you’re a HIIT or weightlifting girly who's interested in learning more about the benefits low-impact exercise. Key moments: 00:35 Quick trigger warning (body image, eating/exercise disorders) 01:37 History of Sam’s HIIT workout obsession 02:55 Origin of Sam’s weird relationship to food and exercise 04:47 A time when Sam literally didn’t work out at all (off-brand lol) 05:43 The downside of having a good metabolism in college 06:03 How Sam established a solid workout routine for the first time 07:35 How Sam’s love affair with Rumble Boxing began 09:03 What changed 10:17 Feeling bloated, puffy, and exhausted from HIIT workouts 11:17 HIIT/weightlifting ego bias against low-impact workouts 11:35 The Pilates girlies might be onto something 11:57 What if your go-to workout has simply…stopped working? 12:20 The relationship between high-intensity workouts and cortisol 12:52 How cortisol can be good for you 13:05 What happens when you produce too much cortisol 13:49 How you can become desensitized to anti-inflammatory responses 14:23 How cortisol affects your thyroid and your metabolism 17:00 Why recovery after a workout is actually effective for reducing bloating and puffiness 17:15 Vasodilation—one reason you’re feeling inflamed after high-intensity exercise 18:52 How high-intensity training can mess with your sleep 19:56 How sleep-related inflammation affects your brain (not just your body) 20:32 The vicious sleep-cortisol cycle 21:05 How high-intensity workouts make your body retain fluids (leading to puffiness) 23:16 Why HIIT isn’t always the best for fat burning (low-intensity might make you lose more weight) 23:57 “Toning” your muscles is a myth—here’s the truth and how to achieve it 25:46 The bottom line on cortisol in workouts 26:14 The importance of moderation (in everything) 27:35 Upcoming episode topics Thanks for listening! New episodes are released every Sunday at 8 AM ET, so if you liked this episode, subscribe or follow to get notified about the next one. And please leave me a rating or review, so I can continue to improve the show. Talk soon! Follow along: Instagram: www.instagram.com/lifeincapslock TikTok: www.tiktok.com/@lifeincapslock YouTube: www.youtube.com/@lifeincapslock Threads: www.threads.net/@lifeincapslock Resources for this episode can be found here. Learn more about your ad choices. Visit megaphone.fm/adchoices