Some good advice here.
I especially like the seemingly wise *ss recommendation to play more tennis. It seems obvious but to really master tennis its thought you need 10,000 hours. The thing is the pros have all mastered tennis - and we mostly have not. Thus when they hit their 10,000 hour mark they can focus on improving fitness and athleticism. For us more time on the court is going to reap the greatest benefits.
I like the advice about injury free mass. People get a little passionate about weightlifting. People are going to want to lift no matter what. So the key is to know that in truth many different exercises strength will reap modest benefits. While its true some exercises are better then others the key point that most tennis players need to be concerned with in my experience is avoiding injury while getting stronger. So if you can do for example overhead presses and bench presses with absolutely no shoulder pain - go for it. Lots of guys I know hurt their shoulders doing it though - and they could get similiar results doing say neutral grip dumbell presses and no shoulder pain.
Now to answer the question of what is the best gym exercise? That would be jumping rope - it helps quickness, coordination and endurance. And personally I feel thats what most adult male opponents lack. I say this because i have hit with juniors who use excellent technique, speed, and endurance to play much better tennis then the much stronger adults..
I think people don't want to hear this because they like to think the bigger muscles are going to make them awesome at tennis - but the crossover seems really really small. Lifting might be fun for the ego and good for overall health and useful for everyday life. But with regards to improving tennis directly for low level players - its way down the list.
Last edited by GuyClinch; 05-04-2013 at 09:58 PM.