# @mackinprof on Instagram

- **Type:** Image
- **Original URL:** https://www.instagram.com/p/DI3IdDwOuz1
- **Gondola URL:** https://gondola.cc/posts/59739756-mackinprof-instagram
- **Thumbnail:** https://img.gondola.cc/tr:w-,h-,fo-auto/postThumbnails/283a96d374.jpg
- **Posted:** 2025-04-25T07:37:57.000+00:00
- **Account Owner:** Stuart Phillips (@mackinprof) — https://gondola.cc/mackinprof

## Caption

💥 New (old) science drop: Cortisol was the only hormone that actually tracked lean‐mass gains—while GH, IGF-1 & Testosterone showed zero correlation with hypertrophy or strength! 📊💪
 
Why? All that talk about chasing post-workout “anabolic” spikes? It’s mostly hype. 🤯 Time to focus on what really moves the needle.
 
🔍 Dive deeper: West & Phillips found cortisol AUC vs. ΔLBM r=0.29 (P=0.03)—no such luck for GH, IGF-1 or T  https://link.springer.com/article/10.1007/s00421-011-2246-z (DOI: 10.1007/s00421-011-2246-z)
 
🔍 For the full myth-busting primer on endogenous hormones in muscle growth, see “Hormones, Hypertrophy, and Hype” https://journals.lww.com/acsm-essr/fulltext/2024/10000/hormones,_hypertrophy,_and_hype__an.2.aspx (DOI: DOI: 10.1249/JES.0000000000000346)
 
It's time to stop all the BS talk about how cortisol is the bogey-hormone destroying your gains, causing you to gain fat mass, and wrecking your metabolism. As an indicator of stress, cortisol, epinephrine (adrenaline) and norepinephrine (noradrenaline) all go up in response to exercise; it’s completely normal for this to happen! The chronic elevation of these hormones and your sympathetic nervous system isn’t good but is addressed through adequate recovery – when your body says to slow down, listen to it. Eat sufficient energy and protein. Master your sleep. No need for pre-exercise eating; working out fasted is fine and will do NOTHING to hurt gains or elevate cortisol and cause muscle to be lost!
 
#Health
#WomensHealth
#Muscle
#McMasterUniversity
#FitnessScience
#NoBroScience
#HormoneHype
#MuscleGrowth
#LiftSmart #CortisolOnly
#LeanMassGains
#MuscleHypertrophy
#ResistanceTraining
#HormoneScience
#EvidenceBasedFitness
#NoBroScience
#FitnessMyths
#AnabolicHype
#Cortisol
#GrowthHormone
#IGF1
#Testosterone
#DataDrivenFitness
#StrengthTraining
#MuscleGrowth
#FitSci
#LiftSmart
#ScienceBacked

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## Tags

liftsmart, musclegrowth, mcmasteruniversity, resistancetraining, leanmassgains, growthhormone, cortisolonly, sciencebacked, muscle, hormonehype, musclehypertrophy, testosterone, fitsci, anabolichype, igf1, hormonescience, datadrivenfitness, strengthtraining, nobroscience, fitnessscience, evidencebasedfitness, cortisol, fitnessmyths, womenshealth, health

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