The idea that you start losing a significant amount of muscle at 40 has been floating around for decades, but it’s based on outdated research and oversimplified messaging.
In this episode, Coach JK revisits where that belief came from, how it spread, and what newer data actually shows about muscle loss as we age.
He breaks down why the “cliff at 40” story doesn’t hold up, what really happens closer to 60, and how much of it comes down to lifestyle, not age.
From training consistency to protein intake, movement, and recovery, this episode reframes the conversation around what aging and strength really look like.
Referenced studies:
Lexell J., Taylor C.C., Sjöström M. What is the cause of the ageing atrophy? Total number, size and proportion of different fiber types studied in whole vastus lateralis muscle from 15- to 83-year-old men. J Neurol Sci (1988).
https://pubmed.ncbi.nlm.nih.gov/3379447/
Volpi E., Nazemi R., Fujita S. Muscle tissue changes with aging. Curr Opin Clin Nutr Metab Care (2004).
https://pmc.ncbi.nlm.nih.gov/articles/PMC2804956/
von Haehling S., Morley J.E., Anker S.D. An overview of sarcopenia: facts and numbers on prevalence and determinants. J Cachexia Sarcopenia Muscle (2010).
https://pmc.ncbi.nlm.nih.gov/articles/PMC3060646/
If this episode helps you see aging differently, share it with someone who needs the reminder that strength doesn’t have an expiration date.
Instagram: @coachJKmcleod
Email: JK@jkmcleod.com