Tissue replacement preserves recovery

This proposal asks whether replacing tissues at 60 could preserve recovery after illness or inactivity and slow lasting decline. It combines 20% of gluteofemoral fat, energy-storing tissue around the hips and thighs, with 20% of complete motor units, nerve-to-muscle structures, in quadriceps and soleus, including tendons. The test compares this set with muscle-fibre grafts, visceral-fat replacement, or tendon or neural omissions. Only the complete set is predicted to preserve recovery across five clinical domains; isolated strength or insulin-sensitivity gains are insufficient. Rival hypotheses could overlap. Studies must use equivalent care, account for pathogen exposure and starting burden, and track survival. Whether this mechanism works in people remains unknown.