For years pot was a big stigma for martial artists. Many used the ancient mysterious herb in secret, but then denied using it if asked about it in a public forum of course. Drugs of various types have always been associated with the martial arts over thousands of years. Opium, pot and hashish have all played a role in shaping the lives of many martial masters. Whether condoned or not, the constant presence of these substances in the martial arts field is a fact. I suppose there is both good and bad tales which have sprung from it. Each has it's warnings, benefits and drawbacks. 
Read more about such history here: 
Opium usage in the Southern Chinese martial arts

Kung Fu Master & Opium Trade  -
For the most part martial artists agree that smoking a little pot prior to practice allows them to flow freer and create easier. By create I mean to access real spontaniety while in the flow of action whether it be practice or combat. This ability to tap into a "better place" has lead to discovery and breakthrough for many masters. Without the aid of weed there are many fighters who say they'd probably be in jail. The weed gave them mental focus and a personal calm, it shifted their perspective just enough for them to turn things around and form their life in the positive manner nature originally intended for men of such inclinations. 
http://www.hightimes.com/read/eddie-bravo-marijuana-martial-arts-master

The arts themselves have a very distinct spirit too, a sort of saving grace about them. They are like a deep well from which martial artists can draw from to resusitate their lives in a variety ways. People always see the destruction associated with the martial arts but rarely see the other myriad positive effects they bring. It is these life enhancing effects that really make the practice of martial arts so valuable to most of us. And it is these same effects that pot really brings into sharp focus. For those people leading a true martial arts lifestyle smoking a litttle pot helps find one's so called "center". An important aspect which is part of nearly all martial pathways. The awareness of life and the appreciation of meditative movement is found through the gentle guidance of this divine herb.
While I've also heard that many martial artists enjoy lifting a mug of brew or two every now and again. I suppose for those folks who enjoy that it too is just fine. But an old saying goes like this: "with booze ya lose" - and it's true. Pot heads have little or no inclination for senseless violence, where as drinkers are notorious for starting stupid shit storm's at the drop of a hat. While booze and the arts seem to also have found a special niche in which to reside it is an entirely different universe in which the drinker dwells from that of the world of the marijuana based martial enthusiast. No more need to be said here as we all know what I speak of. If I had to choose between a quarrelsome damn drunk and a stoned pot head I'd take the smoker every time! Each person has a way, for some booze is the thing. To each their own, I pass no judgements! Lean and green for me!

The element of marijuana in the martial arts is a mere shadow compared to the illegal drug use we are seeing crop up in every sport! Including martial arts as shown here: http://www.fighting-mma.com/mma-news/mma-steroids.php
and here :  
http://www.blitzmag.net/people/bjj-mma/515-drugs-in-martial-arts-how-big-is-the-problem

These drugs are indeed harmful and cause irreparable damage to the martial artist who uses them too often. Between injury and drugs it seems today's martial men are making some bad choices about their future and long term health. Marijuana could save these guys some pain if it were seen as a benefit. Concentrating upon the harmful substances is a better way to clean up the martial arts than to spend time demonizing something everyone else is so over. Marijuana is legal now! Get over it you who oppose the green and move on. you'll be better for it! 
We as a community have bigger fish to fry!
While many Guro's teach us that there are no shortcuts to enlightenment or ability it does seem that smoking a little pot can sort of speed things up some. Remember we seek "enlightenment" and enlightenment is not bliss. To achieve a breakthrough in understanding of our chosen art(s) is the goal, a type of minor samadhi. These little discoveries made by the weed enhanced martial artist are often worth their weight in gold. Total (grand) samadhi is another thing entirely, it often takes a lifetime to achieve. So while we shan't say that weed alone brings about an awakening, we might conjecture that weed and martial arts (yoga, dance, etc) in combination do indeed bring about rapid shifts, changes and minor enlightenment's that are both emotionally enjoyable and physically beneficial in the mysterious martial manner which we so diligently pursue. 

In times past many martial artists sought divine assistance through visions, dreams and ritual ceremonies. Even our humble Karate arts were once exclusively practiced in graveyards due to both secrecy and the quest of spirit interaction. The ingestion of or the smoking of marijuana has long been a means to find one's spiritual helper. The aspect of ancestor worship also play into the greater picture. The sacred herb is said by some to help connect the world of the deceased with that of the living. The two planes of existence are well known and have long been a part of the mystical teachings that comprise the basis of spiritual martial arts. Even Hollywood recognized this about the martial arts when the made the movie "Big Trouble in Little China". Smoke, mirrors, immortality, gods and demons... a reflection of the true inner and outer martial reality. 
Once that marijuana was banned in America other places soon followed suit. The media and it's stooges played the "devil weed" aspect up way past realities limits. Hence the good herb was demonized by the so called "controllers". They could not have free thought, free men or free enterprises coming about and pot gave men freedom most of all. So in all honesty it had to be stopped. And it was for the most part. While cigarettes and booze flourished, both products killing thousands as they went along in daily life, weed on the other hand simply disappeared from our radar entirely. That was until the sixties and then the hippie movement changed all of that forever. Finally in 2015 we are seeing reasonable change in these stupid laws regarding marijuana. Finally we can access healing, enlightenment and centering without the fear or stigma of the bad old days. Weed has went from being a media based bad thing into being an incredibly good thing on many levels of life!

Marijuana does not have to be an adolescent stumbling block any longer. It never was in the first place. More media BS. It has always been a sacred plant that helps and guides us. Nearly all tribal people know this.  http://www.rense.com/general96/waronweed.html
 Finally it has came full circle and is realized as a true sacred plant - not a damn "drug". But simply for what it is, a beneficial plant. For many people the associated social stigma's connected with pot were just too much. So they avoided it at all odds, once urine testing started even more people shunned the green wonder. This is too bad, in their timidity they are lesser for it. Now as legality looms in all 50 states there is no reason for those of you who have been curious about pot and it's positive effects not to try it. And yes, training is also recommended.. relax and the breakthroughs are there like magic! The next level of performance awaits and the gateway to this higher understanding is the green machine from the creator that men have called the "weed"! 
In martial arts injury is not uncommon. As the martial artist grows older these injuries begin to add up. Sure there are drugs and surgeries one can have. But is that really what most of us want? Really? Are not the pain management aspects of marijuana worth looking into before you go under the knife? Marijuana controls pain well and does so with no negative side effects which regular medicines often entails. The healing properties of marijuana leaf, oil and bud is a well known fact. It fits into the realm of all martial arts lifestyles in some manner. This alone is a strong vote to give pot a chance.
It's my belief that what we are currently experiencing with the multi-state legalization movement is a "bubble" of sorts. A short term thing at best. I have serious doubts that this wonderful, enlightening gift from God will be around for too long. It's simply too good for the masses for the controllers to allow it! There is already lawmakers and control fiends making up lies and excuses to get some counter-legalization bills passed. They are bizzy beavers of bullshit, but eventually they will get their devious plans accomplished. I may be wrong, but it's best to stay on guard in these matters. This is a time to "be calm", stay cool etc.. as never before. Just consider yourself to be upon "thin ice" all of the time. Daily life has became thin ice. Walk easy, talk easy, smile, nod and laugh. Learn to take your time. See & think ahead. Stay lean, green and grey Jose! (if ye get my meaning) -