I should, but I don't. I do hike four hours a week and swim for a half hour every day very early in the morning. Thanks for the reminder, you are 100% correct. I am in my mid 70s, so I think I only need resistance training about twice a week.
Here's an exercise anyone can do almost everyday that will increase bone density. I do it in the shower or wherever there's a solid safe tile floor:
Start with both knees and hips bent (like a football linebacker just before the snap), legs apart and arms bent at the side to maintain balance. Set one foot slightly ahead of the other. Now, using primarily the heels of your feet, jump up slightly(preferably only a few inches) and slam both heels back down, while switching which foot is forward. [Don't jump so much that you straighten your legs; instead keep knees bent at all times]. You're hopping in place and striking your heels on the ground, with the right foot forward first and then with the left foot forward, back and forth. Make sure the heel hits the tile and bears the brunt of the force (rather than the toes). Do 20 of these hops each time you're in the shower.
Slamming the heel of the foot into the floor vibrates the large bones of the legs. These vibrations will strengthen (all of) your bone over time.
