This is an interesting 16 minute video — Rebuilding Mum & Dad: See Frailty Reversed Through Strength Training | 5-month Update:

catch up on my parents’ progress five months after starting weight training in their 80s, as they work to rebuild lost muscle and retain their independence.

See my dad grow in confidence as he takes on heavier weights, and watch my mum’s incredible progress with her mobility as she walks longer distances unaided.

So glad I've taken up weight training at 70.