Randomisation
The participants were randomly assigned to either the intervention group
or the control group (ratio 1:1) at baseline by a computer-generated
random sequence, using random permuted block randomisation sizes (four,
six or eight). Proper concealment was accomplished through the use of
external randomisation service (Clinical Trial Unit, Department of
Clinical Medicine, Aarhus University, Denmark). Each participant´s
Central Personal Register (CPR) number was entered in the computer
program (Trialpartner) by a research midwife, and thereby each
participant was allocated to a group. The researchers were involved in
inclusion of the participants and while the intervention consisted of
exercise, neither participants nor researchers were blinded to group
allocation after the randomisation procedure. The statistician
performing the analyses were not blinded to the group allocation due to
the prespecified perprotocol analysis.