You’ve heard the warnings—“HIIT spikes cortisol!” “Stop doing intense workouts or you’ll never lose weight!” In this episode, I’m diving into these claims to separate social media myths from science. What is HIIT, what is cortisol, and what do experts and peer-reviewed research actually say about the two? If you’ve ever felt confused about whether high-intensity training is helping or hurting your hormones, this one’s for you.

What We Cover in This Episode

• A definition of HIIT (High-Intensity Interval Training)
• What cortisol actually is and why we need it
• How cortisol naturally fluctuates during the day—and during exercise
• Common myths and claims from influencers (yes, we name a few)
• Why HIIT does temporarily raise cortisol—and why that’s not a bad thing
• The truth about under-eating, recovery, and chronically elevated cortisol
• Smart ways to listen to your body and optimize recovery

Key Takeaways
🔥 Cortisol is not your enemy—it's your body's way of mobilizing energy.
📈 Intense workouts temporarily raise cortisol, but levels return to normal (or below) within hours.
🥗 Chronic cortisol elevation is more often tied to under-eating, not just working out hard.
💡 Influencers oversimplifying this conversation are often leaving out science and context.
💪 Sleep, fuel, and variety in movement are your friends when it comes to hormone health.

Further Reading
What is Cortisol–and should you actually be worried about it? (published in National Geographic in 2024)

Cortisol Rises During Intense Workouts. Is that Really a Bad Thing? (published in National Geographic in 2025)

"Acute effect of HIIT on testosterone and cortisol levels in healthy individuals: A systematic review and meta-analysis" (Published in Scandinavian Journal of Medicine & Science in Sports in 2021)

Connect with me on Instagram! I'm @strongher.collective.