I posted this on a golf instruction forum and thought it would be applicable here.
I know tons and tons of stuff about physical training from personal study and experience. I'm not a physical trainer or anything like that but I have a background in the stuff that would top most "certified" trainers that work out of local gyms. In my opinion trying to follow or develop a golf specific fitness program is a waste of time and can actually lead to a decrease in performance. If you want evidence look at the training that is done by athletes in other sports. Basketball players don't follow programs that are basketball specific. They follow programs that develop overall strength and endurance and movement in all directions.
Most of your really good athletes in any sport were also really good in other sports. I believe this is true because playing more than one sport develops a balanced athlete and they learn to move their bodies in any direction not just the directions needed for their primary sport. This has been proven over and over again by people a lot smarter than I am.
I'm experiencing really, really good results working with a program that stresses overall improvement in strength, athletic development, and movement. I've also started some mobility work that shows a lot of promise. I didn't develop either of the programs and I'm not affiliated with them in anyway. It's free for anyone to follow but it's very difficult if you have no background in physical movement. I'm not comfortable posting the link here because this isn't my website and neither is the one that post the workouts. If you want to find it do a search for cross training and you'll get pretty close. If you want specifics you can PM and I'll give you the links to the two programs I'm following.
I'm also not going to be so bold as to say what I'm doing is the best programming on earth but it's the best I've found so far. The key is balancing improvements in strength, movement, and endurance.
It would be a very good idea to work with a trainer for a little while that can at least teach you correct movements so you don't hurt yourself. Just don't tell them you want a program to improve your golf game.
This is my blog so I'm not afraid to say that the programming that I'm currently following is outlaw crossfit and I also use mobility WOD. You don't have to be a super athlete to follow the mobility WOD site. In my opinion the mobility WOD is something everyone should follow regardless of age or physical ability.