Although the association between low birth weight and sarcopenia is well established the underlying mechanisms are not understood. We have recently shown that is feasible to collect muscle tissue from older men and women living in the communityref9. This has enabled us to embark on mechanistic studies. Our first investigations assessed differences in muscle morphology; in older men who were of lower weight at birth weight, their muscle fibre score (a proxy of total fibre number) was reduced (see figure). This difference could not be explained by effects of age, height or level of physical activityref10.