When I was 20, I worked for a life insurance company, so I learned early that I needed to save for retirement. Of course, it wasn’t easy. There were bills to pay, then full-time childcare expenses, for twins, then a career change. Even so, mostly thanks to my husband’s employers, we were able to put some money away and have a head start on a retirement nest egg.

It wasn’t until my late 40s, however, that I learned that money isn’t the only thing I needed to save. When writing an article about osteoporosis, I realized that I should have also been stockpiling muscles.