Posture...

I have two near neighbours who are both in their seventies, the first, Jane, walks her dogs daily, does over 60s yoga and attends a biweekly fitness class that includes weights.  The other, I saw being collected today by the care in the community mini bus, she can barely walk down the path to the bus and is practically doubled over her spine is so weak.
I should make a disclaimer here to say I don't know if she has suffered chronic illness in the past and if this is the cause of her state or if it is just degeneration.
Spending time exercising isn't a selfish thing to do, it is saving hours of work and extra care for our families when we are old and unfortunately the future of 'care' looks bleak, aging is a reality that we must be prepared to deal with ourselves.
As we have dogs, I see Jane regularly, her husband died in his forties and this was when she really started to exercise in earnest, she puts her good health down solely to sustained exercise over a long period of time.  She loves wine and good food, and is by no meas treats her body as a temple, but exercise has been the structure around which her day is built since her mid forties.
As long as you use it, that gym membership is not a luxury that you should feel guilty about.
Since she has always done yoga, she has a very strong straight spine, and for those who for whom gym membership does not work, conscious movement (incorporating LOTS of walking) can be enough to stave off the decline described above.

As we all spend time on computers, the 'widow's hump' is appearing on younger and younger people. Unfortunately especially young men, who I often see with the rounded back and extended neck that protrudes in front of them like a turtle. It is a depressing thought, that even in their twenties, once they are habitually in this stance, it is almost impossible to recover from it.

Ignore the age profile, this can happen at any age....

 This was the only picture that I could find that illustrates it clearly on a person, if you watch people go by on any high street, you will start to notice how many young men are already as extreme as this, the posture should be rechristened the computer geek hunch.

In total contrast to this, think about Jessica Ennis at the Olympics, who wasn't on the edge of their seats, holding their breath waiting for her to run, jump, throw and just generally achieve something superhuman?
Do you remember how she used to roll back on her feet and extend the length of her body by pulling in her core, pushing her chest high, tightening and raising all of the muscles in her legs, as she rose on to her toes and slid her shoulder blades down her back.

So many people bring their shoulder blades up around their ears when they think about sitting up straight, but for the spine to continue its natural line, we should imagine being lifted by the chest, with our shoulder blades sliding down our back and our core tight for maximum chest height. This also naturally forces us to tuck our chin in so that the head does not flop forward.

At the Spirit of Summer I will be doing a posture work shop, if anyone wants tickets to the events. Read this post