Orphanet J Rare Dis. 2025 Jul 7;20(1):346. doi: 10.1186/s13023-025-03869-z.ABSTRACTBACKGROUND: Marfan syndrome (MFS) is a rare connective tissue disorder adversely affecting several organ systems. This study evaluated the physical fitness and level of physical activity of Swedish adults with MFS with particular reference to age and sex.METHODS: Included were patients with MFS aged ≥ 18 years, registered in the physiotherapy registry at the Adult Congenital Heart Disease unit of Sahlgrenska University Hospital/Östra who had completed at least one physical fitness test.RESULTS: Of the 1,894 registered patients, 41 met the inclusion criteria, and 17 (42%) were women. Women with MFS had lower exercise capacity (85.8 [32.3] vs. 123.0 [33.4] W, p = 0.003) and muscle function (handgrip strength 57.6 [18.8] vs. 117.4 [37.3] lbs, p < 0.001; shoulder abduction: 4.4 ± 1.5 vs. 7.4 ± 1.9 kg, p < 0.001) than men with MFS. Adults with MFS had significantly lower exercise capacity than reference values (p < 0.001). Both men and women with MFS had decreased muscle function (left and right heel lifts: p < 0.001 for both; handgrip strength: p = 0.021 for women; shoulder abduction: p < 0.001 for men; timed-stands test: p = 0.007 for women, p = 0.009 for men; compared with reference values. Overall, 71% of the patients reached the current physical activity recommendations of 500-1,000 metabolic equivalent of task (MET) minutes per week.CONCLUSIONS: The majority of adults with MFS were sufficiently physically active; however, physical fitness was reduced. Further research is needed to determine whether individualized exercise regimes can improve physical fitness in adults with MFS.PMID:40624548 | DOI:10.1186/s13023-025-03869-z