2.1. Study Design
This was a two-arm, open-label, parallel randomised clinical trial conducted between February 2016 and December 2017 at the Nutrition and Dietetics facilities of the Faculty of Medical School of the University of Federico II of Naples, Italy. Laboratory analysis was completed in December 2018 at the University of Newcastle. Subjects were randomised into either a CR-alone (control group) or CR-plus nitrate-rich beetroot juice (CR + BRJ) intervention groups. This single-centre study was approved by the Ethics Committee of the Faculty of Medicine of the University Federico II of Naples, Italy (Approval No.: 8615). All subjects signed informed consent before participating in the study. The protocol was registered retrospectively with the ISCTRN database (ISRCTN59029976).