The purpose of this study was to examine the feasibility and acceptability of remotely delivered, home-based exercise programmes on physical function and wellbeing in self-isolating older adults during the COVID-19 pandemic. In a four-arm randomised controlled trial, 63 participants (aged 65+) were allocated to one of three home-based daily (2x 10-min) exercise interventions (exercise snacking, tai-chi snacking, combination) or control (NHS webpages). Functional assessments were conducted via video-call at baseline and four-week follow-up. A web-based survey assessed the acceptability of each exercise programme and secondary psychological/wellbeing outcomes. Ecological momentary assessment data, collected in week one and four, explored feeling states as antecedents and consequences of exercise. All intervention groups saw increased physical function at follow-up and displayed good adherence, with exercise snacking considered the most acceptable programme. Multilevel models revealed reciprocal associations between feelings of energy and exercise engagement. Further studies are needed with larger, more diverse demographic samples.