Methods: 16 subjects will be examined during 40-h TSD, both before and after 7 weeks of interval exercise training. Vasodilatation induced by ACh, insulin and heat (42°C) as well as pulse wave velocity (PWV), blood pressure and heart rate (HR) will be assessed at baseline, during TSD, and after one night of sleep recovery. Biomarkers of endothelial activation, inflammation, and hormones will bemeasured from morning blood samples at 07:00