Abstract Aims To assess feasibility and safety of estimating VO2 max using a SmartWatch and the Rockport Walk Test, and to assess robustness of the protocol for a pilot study on oesophageal adenocarcinoma patients. Methods This prospective feasibility study included ASA grade 1 adults with a SmartWatch. Participants walked 1 mile on the flat, and end heart rate and time taken were recorded both via SmartWatch and manually. Pre- and post-exercise questionnaires provided. Estimated VO2 calculated using the Rockport formula. Results Ten participants (five female), mean age 32.8 (25-37). Mean heart rate via SmartWatch 107.25bpm (80-133) and manually 104.6bpm (84-120). Mean time to complete 1 mile 15:17 minutes (13:08 – 16:48). Average estimated VO2 max 43.6 (41.57- 50.03). Pre-activity 100% of participants found instructions clear and easy-to-follow, and were confident to undertake the activity and complete it safely. Although pre-activity 20% of participants were not confident in finding a suitable flat location and 10% not confident with the technology, in the post-activity survey 100% of participants found it easy to find a suitable location and easy to measure, record and upload their results. One user highlighted difficulty with manually measuring heart rate, and another noted challenges with road crossings disrupting their walk. Conclusions It is feasible to measure estimated VO2 max remotely using wearable technology and a validated test such as Rockport Walk Test in healthy adults. This study highlighted several areas of protocol improvement to deploy the study in oesophageal cancer patients to minimise potential risks and optimise safety and usability.