The benefits of regular activity and exercise are well established, yet a third of the population of the European Union does not achieve the recommended levels of activity. For patients with haemophilia, some activity can cause bleeding into joints, leading to potential joint damage, whereas other activities can protect the joint from bleeds and further destruction. This study investigates the understanding and experience of exercise and activity in people with haemophilia (PWH). We conducted semi-structured interviews with six men with severe haemophilia using a consecutive sampling framework and Interpretative Phenomenological Analysis (IPA). We identified five themes: • “I don’t think about haemophilia, I’ve just got to deal with it” A level of acceptance of awareness of their condition, but they do not want it to rule their lives. • “I don’t let my limitations hold me back” Striving to find activities they can participate in, despite joint impairment. • ”The worst thing anyone can do is stop being active” Belief that activity helps to strengthen joints, gives confidence and improves both body and mind. • ”The best thing they did was to not wrap me up in cotton wool” Knowledge of haemophilia, how to treat and recognise bleeds, and finding activities to suit their bodies. • “Time constraints at home” Common barriers to exercise, as in the general population. Our findings provide clinicians with insight into understanding the barriers to exercise and activity in men with severe haemophilia. This can help clinicians to offer the most appropriate support and allow PWH to find an activity or exercise that suits them. Our findings demonstrate that even those with severe haemophilia wish to remain active and do not want to let their limitations prevent them from exercising. Findings also indicate that being given the education and freedom to make independent decisions about exercise and activities are valued. This suggests that clinicians need to provide a therapeutic environment where their patients can feel safe to make sensible choices about types and level of activity.