Skjølsvik ET, Hasselberg NE, Dejgaard LA, et al. - Researchers examined links between exercise exposure and disease severity in patients having lamin A/C genotype, given lamin A/C cardiomyopathy is known as a malignant and highly penetrant inheritable cardiomyopathy. Participants were inquired for exercise habits from age 7 years until genetic diagnosis. Exercise hours > 3 metabolic equivalents were recorded and cumulative lifetime exercise was computed. Depending on lifetime exercise hours above or below median, patients were classified as active or sedate. Experts examined lamin A/C genotype positive patients (n = 69) (age 42 ± 14 years, 41% probands, 46% women) with median lifetime exercise 4160 hours. Active patients vs sedate were more frequently probands and had lower left ventricular ejection fraction and higher N-terminal pro-B-type natriuretic peptide, while there was no difference in age. The reduction in left ventricular ejection fraction per tertile increase in lifetime exercise was found to be 4%, adjusted for age and gender and accounting for dependence within families. Findings revealed worse systolic function among active lamin A/C patients, vs sedate, which happened at younger age. Exercise recommendations in patients with lamin A/C may be improved by taking these findings into account.