Man, this is a great topic.....I remember when I was in my early 30s and moved to Hawaii because of my fiancé , I joined a private club ( first ever ) and played an average of 3 rounds of golf a day, every darn day.....there would be days I would get 5 rounds even but that was all dependent on the number of people on the course.....3 was guaranteed. Then in my late 30s, I actually had to work but I still managed to play 18 holes a day and 54 on my days off, the body held up great and it only got tired after 7-10 days in a row of multiple round days in 100 degrees heat. It was in my mid 40s when suddenly, the body started to feel the effects, play would suffer after the 3rd straight day and there were days I didn't even feel like playing. Then when I turned 50 ! Oh man, Father Time found me and beat my A$$, I actually have more time to play golf but the body will not perform....I would play about 4 rounds a week but I had to space them accordingly and if I played 36 then the next day would be crap and the day after that would be even worse. Now im a few years older and was just having a conversation with my golf buddies about how old we are getting and how distance is suffering and body does want to play everyday. We are scared of what the future holds for us. I love taking golf vacations of several weeks and playing every day and now that I can afford it, my body will not do it. I finally accepted the inevitable. I needed to work out.....I started out real slow...just a few 1-3 mile walks and about 10-15 pushups and a few miserable pull-ups and a couple planks. Its amazing how the body responds to workout, im about 3 months into working out and now I can walk 36 holes on a mountain course and total distance is 17 miles in 100 degrees heat and pushups and pull-ups have gotten to almost respectable levels. About 200 pushes and 50 pulls over 6 sets. My goal is to be able to run 11 miles at a good pace and do 400 pushups and 100 pull-ups per workout. I lost 15 lbs and need to lose another 15. I think the key to working out in your 50s is to accept what your body can do. There is no Pushing it !, Pain is a bad sign and its ok to give up. The body takes much longer to repair itself and it is mandatory to avoid injury. Some days, ill do half a pullup and my elbow feels sore and ill shut down. Drink lots of water and get plenty of rest and eat super healthy and really really limit the alcohol consumption. It pretty much takes the fun out of life but its been over 20 years since I have been in shape and I can actually visualize myself being in good shape in the next 6-12 months baring any setbacks. Oh and cheat days are fine but don't cheat consecutive days !
Good luck to everybody in their 50s or older, it can be done !!!