biostudies-literatureUnknown14Spiekermann J<h4>Background</h4>Klinefelter syndrome (KS) may be associated with a wide spectrum of phenotypic changes including endocrine, metabolic, cognitive, psychiatric and cardiorespiratory pathologies in adults. However, in adolescence the clinical phenotype of KS is not well described, especially regarding physical fitness. The present study reports on cardiorespiratory function in adolescents and young adults with KS.<h4>Methods</h4>Adolescents and young adults with KS were recruited in a cross-sectional pilot study. Biochemical parameters of fitness including hormonal status, a body impedance analysis, the grip strength, the amount of physical activity at home for 5 days <i>via</i> trackbands and anamnestic parameters were assessed. In addition, participants underwent an incremental symptom-lFrontiers in endocrinology1106118https://www.ebi.ac.uk/biostudies/studies/S-EPMC9922696biostudies-literatureCardiorespiratory fitness in adolescents and young adults with Klinefelter syndrome - a pilot study.PMC9922696Spiekermann JSiggelkow HHanusch BHoppner JSchundeln MMKiewert CGrasemann CSinningen KKleber MfalseCardiorespiratory fitness in adolescents and young adults with Klinefelter syndrome - a pilot study.<h4>Background</h4>Klinefelter syndrome (KS) may be associated with a wide spectrum of phenotypic changes including endocrine, metabolic, cognitive, psychiatric and cardiorespiratory pathologies in adults. However, in adolescence the clinical phenotype of KS is not well described, especially regarding physical fitness. The present study reports on cardiorespiratory function in adolescents and young adults with KS.<h4>Methods</h4>Adolescents and young adults with KS were recruited in a cross-sectional pilot study. Biochemical parameters of fitness including hormonal status, a body impedance analysis, the grip strength, the amount of physical activity at home for 5 days <i>via</i> trackbands and anamnestic parameters were assessed. In addition, participants underwent an incremental symptom-l2023-01-01T00:00:00Z20232025-04-04T11:16:48.279Z2025-04-04T11:16:48.279ZS-EPMC99226963679328610.3389/fendo.2023.1106118