Not being able to do a pull-up doesn’t mean you shouldn’t step up to the bar. Simply hanging on for as long as possible can improve your upper-body strength, Montenegro says. Concentrate on keeping your body as still as possible, and you’ll naturally recruit your abs, hips, and lower back in addition to your arms, she explains, or slowly move your legs in circles or up and down to further engage your abs. 
In addition to diet, exercise and other lifestyle factors can also play an important role in bone health. Smoking and drinking too much alcohol can increase your chances of developing osteoporosis, while weight-bearing exercise (such as walking, dancing, yoga, or lifting weights) can lower your risk. Strength or resistance training—using machines, free weights, elastic bands, or your own body weight—can be especially effective in helping to prevent loss of bone mass as you age.