Perform Ep 25: Intense Exercise & Potential Heart Damage (aka Athlete's Heart)

In this episode, I cover "athlete's heart" — the paradox where the same cardiovascular adaptations that make endurance athletes exceptional can also mimic, and sometimes mask, real risk. I trace the history of what's now known as exercise-induced cardiovascular remodeling (EICR), and walk through what's actually happening structurally, functionally, and electrically in a trained heart. I separate adaptive changes like left ventricular dilation and increased stroke volume from genuinely concerning issues such as hypertrophic cardiomyopathy, atrial fibrillation, coronary calcification, and myocardial fibrosis. I also answer the question, "is too much exercise bad for the heart?" This episode is for endurance athletes, lifters, coaches, along with anyone who might have a family history of heart disease.

Scientific Studies & Papers

• Leisure-Time Running Reduces All-Cause and Cardiovascular Mortality Risk (Cooper Clinic / Aerobics Center Longitudinal Study), Journal of the American College of Cardiology
• Cardiorespiratory Fitness and Long-Term Survival in “Low-Risk” Adults, Cooper Clinic cohort, Journal of the American Heart Association
• Half a Century of Running: Clinical, Physiologic and Autopsy Findings in the Case of Clarence DeMar, New England Journal of Medicine
• Athlete’s Heart Revisited: Historical, Clinical, and Molecular Perspectives, Circulation Research, 2025
• Exercise Volume Versus Intensity and the Progression of Coronary Atherosclerosis in Middle-Aged and Older Athletes (MARC-2): Aengevaeren, Thompson, Eijsvogels, et al.
• Endurance exercise performance: the physiology of champions, Joyner & Coyle, The Journal of Physiology
• Italian elite-athlete cohort studies documenting left ventricular hypertrophy and chamber dilation
• Swedish Vasaloppet cross-country skier database (~50,000 skiers) on AFib risk
• Veteran endurance athlete fibrosis study (~5x ventricular arrhythmia risk in athletes averaging 12+ hours/week for 20+ years)
• Cleveland Clinic JAMA study linking higher VO2 max to lower all-cause mortality across ~125,000 patients

Books

• Born to Run by Christopher McDougall

Tools & Technologies

• ECG (electrocardiogram)
• Coronary CT angiogram (CCTA): non-invasive heart and coronary artery imaging, includes calcification score
• Cleerly: FDA-cleared AI platform for non-invasive atherosclerosis, plaque, stenosis, and ischemia analysis from CCTA
• Heartflow

People Mentioned

• Micah True (“Caballo Blanco”): ultramarathoner who died at 58 during a routine 12-mile run
• Mike Osuna: friend of Dr. Galpin who lost his 15-year-old son Lucas to a sudden cardiac event
• Clarence DeMar: 7-time Boston Marathon winner whose autopsy revealed an enlarged heart with abnormally large coronary arteries
• Paul Dudley White: Harvard cardiologist regarded as the founder of preventative cardiology
• Louis Wolff: Harvard colleague, co-namesake of Wolff-Parkinson-White Syndrome
• Sir John Parkinson: London Hospital cardiologist, co-namesake of Wolff-Parkinson-White Syndrome
• Ben Levine: UT Southwestern sports cardiologist, director of the Institute for Exercise and Environmental Medicine
• Paul Thompson: Chief of Cardiology Emeritus at Hartford Hospital, quoted by Dr. Galpin on the athlete’s heart
• David Epstein: science writer, author of The Sports Gene and Range
• Alex Hutchinson: science journalist and Outside magazine’s Sweat Science columnist
• Michael Joyner: Mayo Clinic anesthesiologist and exercise physiologist
• Reggie Lewis: Boston Celtics All-Star who died of sudden cardiac death in 1993
• Hank Gathers: Loyola Marymount basketball star who collapsed and died on court in 1990
• Joel Jamieson: conditioning coach who discovered a 50% widow-maker blockage at 40 despite ideal lifestyle
• Bill Bowerman: Nike co-founder