 This project will exploit the rapid development of wearable technology to allow perioperative risk prediction to become logistically easier, cost effective and used more broadly. It will use low cost wearable technology to complement or act as a surrogate to complex CPET testing performed for perioperative risk stratification. The data gained from a Garmin Vivosmart HR wearable device, will be used in the community by patients awaiting surgery, and will be correlated with key CPET indices including anaerobic threshold and peak VO2. Ultimately, this study aims to assess whether wearable technology can provide the data needed for the formation of prediction models to risk assess perioperative outcomes in patients undergoing high-risk elective surgery. In addition, an International Physical Activity Questionnaire IPAQ will be completed to compare the activity captured with self-reported activity. This will be combined with frailty scores and handgrip strength as is routinely collected during CPET. Finally, a saliva based genetic analysis will be conducted on genetic variations known to be of significance in critical illness and response to physical stress. This will be delivered by a laboratory Fitness Genes that has developed a bespoke panel of genetic markers ideally suited to this patient cohort. 