The Effect of Progressive Resistance Exercise Training (PRET) on Cardiovascular Risk Factors in Adults With ID.

This study has a repeated time series design with one study group. The study period will last one year and is divided into a 12-week baseline period, a 24-week intervention period (PRET programme), and a 12-week follow-up period. The PRET programme will take 24 weeks and consists of two sessions per week, with at least 48 hours between the sessions. The intervention will be led by experienced physiotherapists and physical activity instructors employed by the care providers. All instructors take part in a training prior to the study. In this training, the intervention protocol and exercises will be discussed and practiced ensuring that the intervention is delivered according to the protocol. Every session consists of seven exercises (RESID) to train all large muscle groups. The programme is in accordance with the ACSM guidelines and characterised by four mesocycles. Each mesocycle consists of six weeks of training. After each mesocycle the training intensity will increase gradually, and within each mesocycle the weights will be adjusted in a way that the intensity remains equal. Training intensity will be measured by the percentage of the heaviest load one can lift for one repetition (% of 1RM). In the first mesocycle, participants are introduced to the resistance exercises and familiarised to the training protocol. They will learn to perform the exercises safely and with good posture. During mesocycles 2, 3, and 4, the number of repetitions will be gradually decreased while the training intensity will be gradually increased until vigorous intensity is reached in the fourth mesocycle (80% of 1RM). The resting time between sets will depend on the training intensity and varies between 30 seconds and 2 minutes. The instructors will register attendance, training intensity, performed number of sets and repetitions, and the weights used for each exercise in a log.