WTB a bra for my elder!

My Sim who mastered body-building just became an elder - and what I don't get is, as well as the body changes (I did make her hair ungrey again), why do they still get strained by working out!? She's been training all her life! Why is she suddenly almost getting heart attacks when she is level 10 on fitness and long-lived, that shouldn't be the case for healthy Sims!