Every morning, unless I’m in a plane or staying in a hotel with small rugs and wood floors, I put a yoga mat on the floor and endure approximately 15 minutes of exercises. Most of them are to help my core, and by doing that, presumably, my balance, stability, endurance and back strength. Some of them are teeth-gnashingly hard (like side planks), but the goal is to get stronger, and, as we all know, muscles don’t do that without a bit of effort.
I get that it’s not as much fun as sleeping later or skipping both exercise and sleep in exchange for a more leisurely breakfast. That’s obviously not a good plan if you want to try to preserve your mobility, not be intimidated by flights of stairs and able to pick up objects heavier than a toothbrush.
So invest in a yoga mat and search online for core exercises on reliable sites like the Mayo Clinic or the NIH. You should obviously check with your doctor before doing anything. But if you get the green light, make it as much a part of your morning toilette as brushing your teeth.