Drink bottled water if you can afford it. Or, pour tap water into a pitcher and place it in the refrigerator for 24 hours. The chlorine will dissipate in that time. Use laxatives, diuretics, antacids and cortisone treatments as little as possible. Yup, they keep your body from absorbing calcium properly.
Resistance training is crucial to building strong bones.
You don't have to put the pin in the middle of the weight stacks. Just lift enough weight so the last three reps of a 12 rep cycle are almost too heavy to press. A 1990 study is eye-opening. H. Klitgaard at the August Krogh Institute in Copenhagen studied master level swimmers and runners. The researchers were hardly surprised these guys were exceptionally fit.