It's not only stronger muscles and a happier ego who will benefit from the training results when somebody asks you how much you bench or squat. Physical exercises, especially with weights, besides providing increased strength and muscle mass, also help in increasing bone strength and density.
Bones are formed according to the level of exposure to physical stress. Once they are exposed to extra weight (e.g. dumbbell squat, Olympic bar squat or dead-lifts), bone cells migrate to the stimulated area and begin creating new layers over the existing ones. Eventually, the collagen, proteins and nutrients released by these cells mineralize making our bones denser and more rigid.
It is important to note that weight bearing exercises using heavier loads and fewer repetitions promote the most significant bone density increases. The Swiss Ball, the five-pound dumbbells, stretching classes, body weight circuits, Insane Zumba Jane Fonda P90X, treadmills or walking, surely bring benefits to our health and well-being, yet as the body adapts, they lack providing sufficient stimulus for continuous bone development and growth.
In addition to using weights, studies show that the benefits are always greater when we give preference to complex exercises that mimic our daily body movements, instead of machine isolated exercises that limit our range of motion and provide lower rates of hormonal and neuromuscular activation.
Give preference to dumbbells, kettlebells and Olympic bars whenever possible and include pull-up variations (weighted if necessary), deadlifts, squats, bench press and military press variations in your training program.
Note: Sitting and waiting until someone decides to include these options in your workout routine will not bring different results at all.
Keep Strong. And Bone Up.