With Tamoxifen, I would when exerting, like walking up a hill, but only after taking Tamoxifen for more than a year. I took it for 3.5 years, and by then I was 47. After 3.5 years I felt like an old woman. HOWEVER, when I stopped it, my youth came back, and I've enjoyed an active life for a long time. I'll be 70 this coming summer, 2025.