Table 3.

Motivations and barriers to participation identified by study participants

Motivations to participation Internal motivations: - Personal reasons Checking health status Comparing own fitness/health to others Improving future health of own family Curiosity/interest Meeting other people/day out - Altruistic reasons For future generations Altruistic attitude in life Previous experience in helping older people (job related) To support research

External motivations: Awareness of being part of a cohort and therefore ‘special’ High quality and good organisation of the study Well established safety record of the study Family recognition of the study quality Being approached/asked

Barriers to participation Anxiety about the muscle biopsy (pain, loss of independence) Effort involved in travelling to the clinic