Fausto is right, to an extent.

You should only do other activities that improve your chess, such as swimming or dancing.  That's right, no girlfriends 

Re! - Back! Full motivated and in best shape (lost 8 kgs) The sky is the limit! 
On next sunday my opponent (IM) will feel my strength - grrrrr!  I can´t wait for my prey! 

@gewgaw:
As TN and others wrote, there is more to chess than (ego-) rating, which is just timely for me, too, because I am just dropping back below 2100. (I wouldn't have to, but there are only few tournaments around here for rating (at least, which is accessible for me), thus no more opportunity this year for correction.)
I, too, am over thirty (born exactly thirtyfive years ago), and don't have the same energy level I had, say, just only at 33. I am also a little bit fat now, compared to that time... Physical condition counts much.
I was told by players at a decent level (2200 and FM) that I already have the potential to reach 2200-2300, while I am able to play horrible tournaments when I make such moves as if I knew nothing of chess, regardless of opponents. (In one tournament I am a match for FMs, while at another I am losing by incredible blunders, not considering even the opponent's next move, against 1800-1900s.) I am very disappointed after certain defeats... 
Should I quit chess, then?  No, I love the game more. I am trying to forget about rating (both mine and the opponent) and concentrate only the board in front of me. 
Just don't care what others think about your abilities. The best state of mind is when you have to look up your own rating in a database when asked about it.

gewgaw wrote on 11/19/10 at 11:42:32:


You don't need to make a decision.  Just stop playing chess for a while.  If you come back then you took a break, if you never come back you quit.  Easy.  But it sounds like you need some time away.

MartinC wrote on 11/18/10 at 10:27:14:

That's what I have done at OTB-chess indeed. A couple of times last years I prepared opening A and behind the board decided to play opening B. Quite amazingly it worked.
One other tip: forget about your rating. It will be OK in the long run anyway. Just focus on the next tournament and even better: on the next game. Enjoy it and try to win it.

Well, you're certainly in good company: look at Fischer.  Different people have different motivations for playing.  Some people play to be sociable; some for pretty much the opposite reason.  If you play mainly to improve, then it could be tough if you come to believe can't improve.

I suppose for myself I regard chess as an art form, and I enjoy the content of the games, and such meager mastery of that content as I may have. I enjoy the study-like paradox that suddenly appears on the board, or the feeling that I've timed a pawn break correctly, or that I understood some new situation in the endgame (you can keep getting better at that for a long time). I also value the post-mortems and social dimensions of the game.  One of my favorite moments occurred during a fairly serious skittles game, when my opponent had a knight on h8, good for nothing except controlling f7 and g6. Suddenly he stopped in wonder at how pathetic the knight looked, and said incredulously,  "it's like a pawn with a stick." That hilarious image has never left me. 

The prospect of losing a few more due to, say, increasing fatigue in the later stages of a tournament--for such factors lie behind age-related stagnation--doesn't bother me; and so I think dropping chess for this reason would be an sad result of the rating system. I mean, even if your rating declines you will still frequently have the experience of winning: checkmate ends the game. But today there is a second game, about statistics, and it is a much less beautiful affair than the first.

There is no rating that could measure the transition from middle-period to late Beethoven; or rather one could be constructed, but it would tell you less than you know.

I'm nearly 60 and have been playing competitively for 30 years. My rating is the highest it's ever been. Sure I make blunders, but then I always have.