"It also challenges prevailing views that reduced physical activity in modern societies is the sole driver of age-related skeletal fragility."

But all the current medical advice says "motion is the lotion" for good bone and joint health! The article is interesting but I would not give up my supplemental whey protein or exercise program. Even ocasional circuit training yields better skeletal health. I can see it in the mirror, despite putting on little new muscle. I think it's called "ripped" by the bodybuilders. It takes months but everything changes, posture, strength, energy level.