A good friend of mine who is approaching 70 and has been doing chemo for quite a period was told by his doctor to start hitting the weights (not big weights) as his bone density is falling off due to the long treatment. He has been an avid bike rider for many years and still gets out there with us...so anything he can do to keep the momentum is an upcheck. I can't say I understand all the physiology of it, but weight training (whatever you decide it to be for yourself) seems to be a worthwhile long term endeavor. I don't move the weight I "used to could", but there is satisfaction in doing what I do.