Background: Although evidence shows the positive health effects of\nphysical activity, most of the adult population in Colombia are\nsedentary. It is, therefore, important to implement strategies that\ngenerate changes in lifestyle behaviours. This protocol describes a\nstudy in which we will compare the effects of 12 weeks of high-intensity\ninterval training (HIIT), resistance training (RT) or combined training\n(HIIT + RT) on the improvement of body composition, endothelial\nfunction, blood pressure, blood lipids, and cardiorespiratory fitness in\na cohort of sedentary, overweight adults (aged 30-50 years).\nMethods/design: Sixty sedentary, overweight adults attending primary\ncare in Bogota, Colombia will be included in a factorial randomised\ncontrolled trial. Participants will be randomly assigned to the\nfollowing intervention groups: (1) non-exercise group: usual care with\ndietary support, (2) HIIT group: 4 x 4-min intervals at 85-95 % maximum\nheart rate (HRmax) (with the target zone maintained for at least 2\nminutes), interspersed with a 4-min recovery period, at 65 % HRmax, (3)\nRT group: completing a resistance circuit (including upper and lower\nmuscle groups) as many times as needed according to subject's weight\nuntil an expenditure of 500 kcal at 40-80 % of one-rep max (1RM) has\nbeen achieved, and (4) combined group: HIIT + RT. The primary end point\nfor effectiveness is vascular function as measured by flow-mediated\nvasodilatation 1 week after the end of exercise training.\nDiscussion: The results of this study will provide new information about\nthe possible effect of the programme in improving the cardiometabolic\nhealth of overweight adults, making a more efficient use of an adult's\nresources over time.\nTrial registration: ClinicalTrials.gov ID: NCT02715063. Registered on 8\nMarch 2016.