Vascular Ehlers-Danlos syndrome (vEDS) is a rare, life-threatening connective tissue disorder. People with vEDS have often been advised to limit physical activity, yet the safety and feasibility of structured exercise in this group is poorly understood. This study works with people with vEDS, their families and clinicians to co-design a safe, tailored physical activity programme, then tests it in a 12-week randomised feasibility study comparing the programme with usual care. The aim is to find out whether the intervention and the trial procedures are safe, acceptable and practical, in order to inform a future full-scale trial. Outcomes focus on recruitment, retention, adherence, acceptability and safety, alongside exploratory measures of physical function, quality of life and microvascular health.