Healthy number: How tall you were at age 21.
This target is yours alone, to see if you’re keeping up your vertical peak.
Have yours checked: Annually. If you shrink by more than an inch and a half after age 21, which suggests bone loss (osteoporosis), you should get a bone-density test or a spine X-ray. “About one in every two women has an osteoporotic break or fracture in her lifetime,” warns Thacker. So if you have lost some of your full height at any age and find out that your bone density is low, you’re on notice: Your bones are fragile and at risk for breaking with a minor fall. To protect them, consume a calcium-rich diet and vitamin D, and do regular weight-bearing exercises (like brisk walking or tennis) and strength training. Smoking and alcohol intake can also adversely affect bone health. Take a bone-protective medication if your doctor advises it.