Lot of us in work hitting 50 yrs old this year, any hints or tips,
I am feeling a little sadness lots of Changes don't feel like I used to energy levels are gone,

My advice is to enjoy it. I'm turning 60 this year and your mortality is a little more in focus then let me promise you.

If you haven't already, improve your diet, stop drinking, smoking and do some regular exercise. You will feel younger and healthier.

You'll be fine Nicky. Just relax into it and you'll enjoy things differently to the way you used to. The only thing is you have to do things a little differently, for instance if you go to the gym to recover energy levels then work it up more slowly. Much like going to the pub the body takes a little longer to recover.
Changes are often tricky to deal with but, honestly, a lot of things settle down again.
Try to look forward to things; who knows? You may have another 40+ years to go so it's really only half time.

Good advice especially "trapped in the past" too many of us become old gits.

One more point

Some great advice looking forward is the way ahead, I went out on a Xmas work party, and couldn't believe the energy I still had on the dance floor, I think us generation xers definately had a great time in the 90s with the nightclubs music and partying.
Just need to improve diet and realise that old friends go and new friends come along, and after having worked for 30yrs solid enjoy life more and not worry too much about the future, Time is something I will value more.

I treat every day as a bonus. I did some stuff in my youth,..but survived it.
Whilst I can no longer run marathons, or do anything too sporty, there are still many other ways to enjoy life, with a reasonable degree of sensibility.

I disengage, I turn the page.