Understanding the amount of pressure that the golf swing puts on your body is key to being able to develop a better golf swing, no matter what your age or skill level. If you can understand the impact of swinging an object at up to 100mph over and over again has on your body, your muscles etc then you'll be able to develop the right approach to making improvements.
An immediate area to concentrate on is in building strength in those areas of your body that are going to be put under stress so you can avoid there being any weakness that could lead to serious injury putting you on the sidelines permanently. Even small improvement in strength will lead to increased stamina meaning you'll be able to maintain your performance over the course of a full round. Of course stretching is also a great way to improve your swing, and in fact many people already know of this technique but in a lot of cases they don't bother. Maybe stretching is seen as work or it's not as obvious what the benefits are but in reality it needs to be seen as a technique for improvement by more golfers.
Now, don't think that by ignoring your strength or flexibility training you can ever achieve your ultimate level of golf performance. It is a rare person who is able to muster enough talent to overcome these physical limitations and even instructors are beginning to realise that there is an absolute connection between fitness and the mechanics of the golf swing. And it is this area in which there is the largest divide between fitness and the instructions that can be given. Let's face it when you are fitter and your physical abilities improve then so will your golf swing and overall golf skills.
Naturally the next time you spend time with your golf instructor you will find that when they teach you a new technique you'll be able to learn it much more easily, and the improvements to your golf swing will happen much quicker. This approach of strength and flexibility is the only real lasting method to see ongoing results which will lead to you achieving your best possible golf swing, so make a change today.