Everyone knows the primary reason for the hobby is sex, as good as we can get it, but there are other aspects, more than just ancillary benefits, that become obvious as we get older.  So, I'd like LG's and others' views on these.  
For me, the hobby provides measurable benefits that become more important as I get older -- I'm in my late 60s.  Years earlier, my only interest was sex, the hotter the better.  
A few years ago for no apparent reason I developed high blood pressure that didn't look good.  My doc prescribed medicine, and all was well.  In addition, even without medicine a visit to an AMP brought normalcy that lasted a few days, as did a soothing non-sexual massage at an upscale spa.  The only difference was that the AMP experience brought more serenity and the feeling of well-being lasted a bit longer.
With the doc's approval, I skipped the pills, but massages/hobby alone were insufficient.    
My wife and I live an urban life style -- not wealthy but comfortable, good jobs (she full time, me part time) kids fully grown and established, good friends, cultural and recreational activities, good community, etc.  No demonstrable upsets and we are very companionable outside of sex.  She'd like more affection, not necessarily sex, and I depend on the hobby to fill what would be a big void in my life.  
In noticeable cycles, I experience a buildup in tension that goes for about 10 days, regardless of outside circumstances.  At the end of that period, I'm more inclined to be snappish, more aggressive in conversation, impatient, and jumpy, although I'm generally condidered easy going.  This is not a polar or manic situation.
Recently, I saw a provider I'm very fond of, and booked extra time because she's been working in another city.  After the festivities, our catchup conversation was affectionate, laced with laughter, and her interesting insights on life outside the hobby.  The time flew by.
Later, I felt serenely relaxed, pleasantly fatigued.  That night I slept 8 hours straight through, and my BP was the lowest in months, well below recommended standards.  Although my daily life is happy, that morning I felt serenely content.    
Have there been any reliable studies of the effect of the hobby on participants?  Beyond the impact of sex, that is.  On health, feelings of well being, overall behanior, etc.  I could make a good case that the hobby occupies a unique niche like no other in stimulating positive human behavior and well being, based on  overwhelming anecdotal evidence alone.  And the impact of a great hobby experience is different, and often better than, sex with your wife or SO, going to an AMP or spa, attending a transcendental cultural event, or watching a playoff game with the guys.    
I know respectable older guys who pinch ladies' bottoms and make obnoxious sexual remarks, clearly because they are frustrated.  I know respectable older women who yearn for dancing partners with whom they can have something different than their companionship with non-dancing husbands.  Whether they want something more than dancing, I don't know, but if they do there should be some kind of hobby for women as well.  
Bottom line: we'll never get health insurance for the hobby, but it should be de-criminalized and  sex workers need protection from abuse and exploitation.  Health protection and security for sex workers and hobbyists could also be improved.  Difficult, but not impossible. Reactions? Apologies for the length.

Dear TraumasObserved,

It's not that strange - despite being in your late 60s, you are still subject to testosterone spikes in your hormonal rhythm. How nice! The reason why you feel them is that your body isn't continuously manufacturing loads of T like it used to when you were younger. Now you get a little zing and you feel it. And yes, acting on those spikes is very relieving, I bet.

No, there havent' been any "reliable studies of the effect on the hobby on participants," for obvious reasons. But there have been loads of studies on the effect of regular sex among males of all ages. Clearly, regular sex is a very good way of maintaining mental and physical health.

I would advise you to get a book by Raul Schiavi called "Aging and Male Sexuality." It's filled with studies, conclusions, commentary and it's brilliant. It was written on the eve of the arrival of Viagra, so some of the information is still "speculative" in terms of PDE5 inhibitors. But otherwise, I would urge anyone into observing his physical and mental processes through aging to get this book.

Have fun in the meantime,
the Love Goddess

For me a trip to the hobby farm alleviates symptoms of depression.  God bless you ladies, every one of you.

I accept the explanations. Next question is how can we get our lovely wives and SO to understand that there is something different going on that is not necessarily a threat to them?  I know several instances where loving and possessive wives ruined their marriages because they thought they could control their husbands' behavior, and believed they had a right to do so. I'm not advocating open marriage, which I feel doesn't work except for a very few couples.

The answer to your question, TraumasObserved,
lies in evolutionary psychology. For your enjoyment, please pick up David Buss' book The Evolution Of Desire. Read it, learn it, live it. Yes, it's a pop version of Donald Symons' book, but not a bad one for explicating what goes on in terms of jealousy among both males and females.

Or, go see Nahid Persson's documentary "Four Wives - One Man." It's hitting the festival circuits now. A documentary on a 49 year old man married to 4 wives and looking for a fifth one. It's filmed in southern Iran, where 14% of marriages are polygamous. They're not so happy, those wives, and not for the reasons one might think.

Next question, indeed,
the Love Goddess

and I find the hobby very life-affirming.   I would love to exchange views with you, but you are using an alias.   If you agree, you can send me a pm

I can see u using it as a form of therapy...alot of my gents do but I strongly suggest you not use this hobby as a way to "fall in love" with a provider.It has happened to me and it scares me and gets in the way of my work.I have had this from the other ladies in forums.