I think that there are a lot of studies that the loss of muscle mass is a pretty decent risk for any of us as we age, and there are some theories that we are starting to die after we reach 30.. and of course, if any of us likely realize that  there seem to be deteriorating effects with the passage of time, even though some people do seem to have better genetics than others, I have my doubts that we can completely ignore lifestyle choices.. even though I do consider that diet and sleep might be more important than exercise.

In regards to exercise, and the need to build and/or preserve muscle mass, there must be some attention towards the benefits of resistance training, even though some older folks (and younger folks are guilty of this too) get so much caught up into cardio, so if they do some kind of exercise that requires a lot of cardio, then they might be too tired to even attempt to carry out any resistance training.   Also, some folks who walk a lot become very good walkers, but they still might not be retaining muscle mass as much as they should do, especially when they start getting into their older years.. .. so it becomes more and more difficult to both retain muscle mass and even to build it.  .. so it could be better to at least engage in enough resistance training type exercises to at least attempt some level of maintenance. 

I know easier said than done.. and I think exercise hurts more than it did when I was younger.. and I don't get as many of those endorphin-like feelings. .which may relate to stamina too.. so if you can maintain exercise for a certain period the endorphins can kick in.. and people might get that on a treadmill. .yet harder to build up to it with resistance training since it tends to hurt.

My push-ups are going better than I thought, and I am going to have to keep track in order to try to figure out if I am making progress, and my first set of pushups went way better than I thought that they would because I think that I recall trying to do pushups several months ago, and it did not go very well.. so this time around I was focused on at least trying to see how many I could do in a kind of dry run.. and it did hurt my chest a bit.. so that might mean to try to pace myself a bit in order to build up to it.. but at least I did them flat, and they were pretty full pushups and I did not have to resort to girl-pushups.. meaning doing them from the knees... after a week, I will probably have a bit of a better grasp of where I am at. .and maybe even better after two weeks.. but I am not sure if I can keep it up until $100k .. so we will have to see how that goes... but I am likely not going to end up doing 100 every day.. and so far  with 1.5 days I have only done 50 each day.. and I may or may not be able to get up to 100 today.. I don't necessarily want to push my quantity to such an extent that I end up injuring myself or that I overdo the matter in some kind of a way... "We" should be trying to pace ourselves in these kinds of situations.