Study sniffs out bean - flatulence correlation

Have you ever participated in a farting contest?  Neither have I.

'cough'..

(sound of crickets..)

(sound of silence interrupted with a tiny "pip" sound flatulent)

'cough'..

Campy bathroom humour is definitely not my style.  That's so cro-mag.

A group of researchers with a penchant for discovering the truth about the urban myth that beans make you emit gaseous anomalies were farting around recently and came up with a process for teasing out whether or not people who eat beans produce more melodious gastrointestinal malfeasance than those who eat carrots or non-fart-causing soup... I wonder if one could order that soup in a restaurant.. "What will you be having today sir?"  "What's your soup du jour?" "We have three selections today, a brilliant clam chowder, an ingenious beans/ horseradish/ cabbage combo, and sans flatulensence; our non-farting soup"  "Your other soups fart?"

Server.. "pip".. looks sideways..

The concern of the research team was that peoples flatuphobia prevents them from consuming beans.  Beans are highly regarded by the worlds health authorities and daily consumption of the little (potentially) wind producing nuggets is associated with lowered cholesterol, reduction of overall chronic disease risk, and of course improved gastrointestinal function.

Flatuphobia; the highly regarded urbandictionary.com, informs us that the term initially referred to the fear of accidental bowel movements when farting (see also "shart"), but is now more associated with fear of farting in enclosed spaces such as elevators or in very quiet environments, such as a church service.

'cough'/ "pip"..

A bean walks into a GI track, "We don't digest your kind, partner.." Says the enzyme tender.

"You're going to regret that in a couple hours" says the bean.

The studies bean counters suggest why legumes may cause intestinal gas.. some of the sugars in beans are not digestible by human intestinal enzymes and are broken down by gut bacteria fermentation. Byproducts of this process include olfactory delicacies such as methane and sulphur, as well as hydrogen and carbon dioxide, which are moved out of the body in the form of flatus..

Researchers were keen to point out that there is variability of gas production between people, seemingly playing down the potential wind-farm - bean connection, adding that beans are enjoyed around the world.  Indeed people in Eastern and South African countries consume annually around 50 kg (110 lb.) of beans whereas US residence dine on a mere 7 lb. of the party pleasers.

The purpose of this study was to investigate the perception of flatulence and GI discomfort among those eating 1/2 a cup of beans daily (1).

Study subjects were fed beans and enclosed in an elevator or quiet church service for 12 weeks.  OK that's not totally true, only partially true.  The part about 12 weeks was true.

Perception of flatulence.  Are people unclear as to whether or not they let one rip?  About that elevator thing.. Maybe the researchers are onto something here because when it's totally obvious someone has abused their social contract privileges and sneaked a cheek with a silent but deadly in an elevator, everyone looks around with a disdained accusatory gaze while simultaneously claiming innocence.  Two men say they're Jesus, one of them must be wrong.

If Jesus farted in an elevator would it be heavenly?  "And let it be said that the Son of God did cause a ruffle in his robe and his disciples were lulled with lavender" .. Luke 1:20:19

The study was well designed with randomized crossover trials.  Some participants ate beans and some ate carrots or the previously mentioned special soup du jour, then the groups switched.  The outcome?

Once the smoke cleared less than 50% of people reported increased flatulence from eating pinto or baked beans, and only a 19% increase with black-eyed peas.  Which reminds me of the Black Eyed Peas performance at the 2011 Superbowl.. not their best performance, they stunk out the joint..

3-11% of all study participants, even those on control diets reported increased flatulence.

"Peoples concerns about excess flatulence from eating beans may be exaggerated".  That's a verbatim quote from the study conclusions, I didn't doctor that one..

The caveat? "It is important to recognize there is individual variation in response to different bean types".

Rinsing beans during the preparation process removes a lot of the sugars that cause the colon kerfuffle, so although this study claims that there's nothing to worry about.. ("nothing to smell here people, keep moving"), if you want to further decrease the less than 50% chance that you'll succumb to intestinal sugar sorcery, rinse your beans if canned, and after the soak and also after being cooked if you're using dried beans.

Experiment with different beans to see what your individual response may be, which may be best done alone if you suffer flatuphobia, otherwise churches and elevators appear to be the favoured testing grounds.

I've got some beans soaking now..

"Pip"

References:

(1) Nutrition Journal | Full text | Perceptions of flatulence from bean consumption among adults in 3 feeding studies

(2) I strongly suggest investigating this historic account of.. well.. just check it out..

(3) more background investigation 

Big Breakfast For Weight Loss?

A new study (1) seems to show that eating chocolate cake for the purpose of adding extra calories at breakfast increases total weight loss over 32 weeks compared to consuming the same total calories over a day, but not loading up at breakfast.

I love chocolate cake.  In fact I love just about anything that is chocolate.  Except chocolates filled with caramel.. or mint flavoured chocolate.. and I'm not really into milk chocolate.  OK so I have specific tastes for chocolate; my favorite is anything between 70 and 90% dark chocolate.

I love putting a tablespoon of dark chocolate cocoa into my yogurt.  Maybe two tablespoons.  Yes, definitely two tablespoons.  If I ate a piece of chocolate cake along with my breakfast every morning should I expect to lose fat?  Is that what this study is saying?

Not really.  This study looked at 193 obese men and woman in their late 40's/ early 50's over a 32 week period where their total calories consumed for the day was limited to 1600 calories (men) and 1400 calories (woman).   Everyone in their respective groups was to consume the same total calories over a day, with an intervention group shuffling a little more of those calories to breakfast in the form of a chocolate dessert.

They wanted to discover whether or not eating extra calories in the morning from sweets would influence food cravings later in the day.  It did, but it took a while.  In the first 16 weeks the morning desert eaters lost the same amount of weight as the straight laced eaters, about 33 pounds.  By the time 32 weeks of chocolate breakfast bliss had passed, those not given the self indulgent sweet tooth option gave into cravings, fell of the calorie reduced wagon, and regained 22 pounds of prime real-estate back onto their bodies.  The unabashed dessert dieters lost an additional 15 pounds.

The scientists were also looking at ghrelin levels after breakfast.  The diet with more carbs and protein from the dessert released less ghrelin than those on the lower calorie breakfast.  "Satiety was significantly improved and hunger and craving scores significantly reduced in the.. breakfast + dessert group versus breakfast only group", the study reports.  Ghrelin is a hormone that makes us feel hungry and is produced in the gut.

Another study showed that a bigger breakfast simply added more calories to the total for the day and did not help weight loss (2).

The main difference between these studies? The dessert at breakfast study, which sounds great, had all study subjects placed on a long term calorie reduced diet and observed the ability to stay on such a diet.  The second study looked those voluntarily consuming large breakfasts while not a diet.

In the second study obese subjects who ate more at breakfast simply introduced more calories to their day as they did not tend to eat less than usual following breakfast.

The first study's researchers recommend considering eating more of your total calories for the day at breakfast when on a calorie reduced diet for weight loss.

The second study's team says if you want to lose weight reduce your calories at breakfast so at least you're reducing calories somewhere, which will help reducing total calories consumed over the day.

I say forget about both these studies as neither of them looked at the important weight loss strategy of mindfulness about what we eat and making changes in how we think about the rewards we associate with overeating.  These studies also did not include regular exercise.

When you're comparing red Pinto's to brown Pinto's, you're still comparing the same crappy car.  While it's interesting to look at the different ways the Pinto is crappy, why not look why a Lexus is good, and then go about emulating those qualities?

Studies like this are interesting to a degree, but when the most relevant, and already known successful weight loss strategies are not discussed in the conclusion, or used as a control in the study, we get good science, but poor conclusions.  How can that be "good science"?  We're still discovering what occurs under the conditions studied so our overall understanding increases.  But in both these cases the outcome recommendations are not relevant to an overall long term successful weight loss strategy because the recommendations are myopic: restricted only to the limited scope of the study.

What does the first study really show?  No matter what we eat, or when we eat it, if we eat fewer calories than we consume, we will lose fat, and if we don't work on the source of cravings for overeating, we'll succumb to them.

How about the second study?  No matter when we eat more, breakfast or any other time, if we overeat we'll gain weight.

It feels great to feel released from the habit of overeating by learning to eat healthy and feel good about it.

Let's get out there and feel good about exercise and making healthy food choices.

(1) Meal timing and composition influence ghrelin levels, appetite scores and weight loss maintenance in overweight and obese adults 10.1016/j.steroids.2011.12.006 : Steroids | ScienceDirect.com

(2) Nutrition Journal | Full text | Impact of breakfast on daily energy intake - an analysis of absolute versus relative breakfast calories

Urban Athletes

These are some of the greatest athletes in the world, but they're not going for gold medals.

CBC.ca Player

Is yoga the only exercise you need?

I've done yoga, then stopped.  I Stopped because it takes too long.  An hour to an hour and an half  seemed like too long for just stretching.  I also found it no more effective than regular stretching, and I was concerned about losing fitness by doing yoga. If I replaced my regular strength training with yoga, and replaced my romps through the forrest on my mountain bike with yoga I would get weaker and less fit.

Why?

Before I answer that, I know many who are very into yoga may have steam coming out of their ears right now after reading me refer to yoga as "just stretching".  I get that people believe it's a way of life, that it's about mind-body, inner peace, breathing, balancing. . .  The thing is, each of those things are not dependent on yoga, and yoga doesn't actually do the perfect all-in-one job that people have come to believe.

Yoga does not require as much work as the more taxing weight training I've built up to and there is no way yoga can match the cardiovascular load I get while mountain biking (or running, or swimming, or any aerobic exercise). In fact studies on energy expenditure during yoga show that at best it's less intensive compared to a walking pace (1), or equivalent to a 3.2 kph (1.98 MPH) walking speed (2).

The second study went so far as to say, "yoga..do not meet recommendations for level of physical activity for improving or maintaining health or cardiovascular fitness".  They also offered a caveat, "..incorporating sun salutation postures exceeding a minimum of 10 minutes may contribute some portion of sufficiently intense physical activity.. in unfit or sedentary individuals".

So if you change how yoga is typically done, and modify a specific sequence of poses, namely the sun salutation, you may get some degree of benefit if you're out of shape.  But if you're in shape yoga simply isn't challenging enough to help you add fitness.  Why sun salutations? The sun salutation sequence involves moving from the floor to standing.  There is actual physical work being done here lifting your body mass from lying on the floor to standing.  However a good set of burpee's will expend far more energy and provide a much larger challenge.

Really.. a 2 mph walking pace? That's the intensity of yoga? So why does it feel harder?

It's true that some of the poses require a little effort from an isometric muscle contraction, but most of the discomfort and challenge felt is not from pushing the strength limits of your muscles, but rather the end range of motion of a completely stretched muscle belly.  We shouldn't confuse the feeling of a stretch with the feeling of actual physical work performed.

There are advanced poses that do require a gradual build up of strength, very good coordination, and great balance.  Again though, those are simply our natural human potentials that can be developed with a large variety of different sports and physical activities.  Yoga is not the best, nor the default exercise mode that improves these attributes.

It is "hard" to attempt yoga poses that one isn't flexible enough for, but the actual muscular work performed to achieve that pose is not very high.. in fact it's nearly nothing, with the exception of the most advanced poses.

For those who feel yoga is a good workout it may be best to drop that association belief and qualify yoga for what it actually does.. increases flexibility and helps with stress management.

Push ups will expend more calories and make you stronger than any yoga pose will.

A while back a friend of mine commented on how yoga has been the only thing that has made them more flexible, something regular stretching never did for them.

I asked them how much time they spent doing regular stretching and it turns out it was something they avoided.  I then asked how much time they spent doing yoga; 3 90 minute sessions per week.

I suggested that it may be that 4.5 hours of stretching per week is going to be more effective at increasing flexibility compared to rarely stretching.  4.5 hours.. spent on stretching?  From a coaching perspective that makes little sense as huge proportion of either possible rest time or training time would be disproportionately given over to stretching, which requires maybe 30 to 40 minutes per week in total, depending on the sport and what an individuals needs are.  Adding another 4 hours of stretching is not a useful way to spend our exercise time.  My friend didn't asses their true experience which was that spending more time on stretching than they had ever done before, 4.5 hours per week, increased their flexibility more effectively than stretching infrequently.  Instead they drank the kool-aid and unequivocally believed yoga was special rather than realizing they simply stretched a lot.  Yoga is strongly marketed as bestowing mystical powers of mind-body improvements, and many buy into the sales pitch.

So how does yoga compare to regular stretching? Can such a comparison even be made?  I mean, aren't we really calling the same thing by different names when we call a hamstring stretch a hamstring stretch, and then call it padangusthasana (standing, bending forward from waist), or Dandasana (classic sit and reach)?

The body moves according to it's skeletal and muscle form, it doesn't matter what we name any given position, whether in Sanskrit, english, or any other language..  Call it what you want, when the thigh bone is flexed at the hip, a stretch is placed on the hamstrings (as well as the glute max and a mild stretch on the adductors).

Does yoga change human physiology making these muscles attach in a different way?  Of course not.  There are no "yoga muscles". The physiologic process of stretching is not dictated by "yoga", it's a physiologic response to demand imposed on muscles and connective tissue.  It doesn't matter if a stretch is done in a yoga class or not.  In yoga, you facilitate a stretch the same way any stretch is facilitated.  However in yoga, the natural response to stretching is hijacked, given special value, and this value is falsely attributed to yoga.  Of course the same response would occur anyway, even in the absence of a yoga mat, yoga pants, yoga water bottle, yoga sweat, yoga room, and a yogi guru telling you you're experiencing a special thing that you can only get through yoga.

Study: A randomized trial comparing yoga, stretching, and a self-care book for chronic low back pain (3).

Conclusion of the 12 week study involving 228 adults? Stretching and yoga produced the same results. One would think so, because you're comparing stretching to stretching.  The self help book didn't fair as well.

An interesting note by the investigators, "Yoga was not superior to conventional stretching exercises at any time point".  Good to know.



Random yoga pics from the internet. But maybe not so random. Before you ever get to a yoga class, you're exposed to images and ideas that convey serenity, and the ubiquitous "oneness" with nature or self in some mystery of the universe way. These are appealing qualities. Who among us wouldn't welcome peace of mind. You're already conditioned to expect a certain outcome from yoga, and the way our minds work, we'll often find ways to make sure we interpret that we're experiencing what we expected.



In reality though, we can find this experience in many ways, and seeing images of other activities in serene backgrounds can evoke the same emotive longing. Important to be aware of how we're influenced by images and ideas that we're exposed to over the long term. But if you believe the yoga sunset pictures are more serene than other sunset pictures, it will either be because the picture is reenforcing this previously made association in your brain, or because the photo is framed better, has better colour saturation, and has a more emotive staging.  That's how that works.

From what I've seen, yoga is particularly aggressive at pushing this angle, and insisting a yoga superiority in delivering this experience.  Marketing works.  An interesting twist is that because yoga is slogged as being the ultimate humanistic/ spiritual approach, there is a baked in notion that yoga companies aren't trying to sell you anything.  No, not them.  They're pure soles.  They're simply welcoming you to your new level of self awareness, on special this week for first timers, and if you buy now you get a free yoga mat (regular value $69.99).  Chakra alignments extra.

A sunset yoga pose image reenforces the perception.  You're likely to think it looks great, and that maybe, upon viewing that image from inside the office, yoga is looking like exactly what you need.  But you could also go for a walk, jog, ride, in a park and stretch at sunset.  No yoga.  You'd also feel good after that.

An athlete I train went to a yoga class for the first time and did nearly every pose better than most of the regulars.  The athlete told me they were really good at yoga and felt great afterwards, and that they think the benefits are obvious so they should keep going.  I asked them what made them so capable of doing the yoga poses.  "I don't know, I guess I'm just naturally good at it."  I asked, "could it be all the strengthening and stretching I've taught you over the last year?"  They had the dead pause and replied, "I didn't think of that.. yeah I am definitely way more flexible and stronger since you started training me.. my back doesn't hurt anymore and it doesn't hurt to run."

Did these benefits occur only after this one yoga class you did, or do you think it was the last year of training?"  "Obviously it was the last year of training, one class can't do all that."  Exactly. This athlete doing a standard strength and conditioning program that included regular stretching had them flexible and stable enough to pull off nearly every yoga stretch on the first try.  Why?  Because that's what strength and conditioning does. That's what good quality physical activity does, you don't need to embellish the perception of the natural response to physical activity with phoney woo-woo.

People were dumbfounded that this person was so good at yoga having never done it before.  They had become convinced that only yoga, and only long term dedication to yoga could provide these adaptations.  They didn't realize yoga is simply exercise, and that any well rounded regular exercise will produce good results.

It was interesting to me that this athlete was so willing to attribute his pre-yoga class performance to the single yoga class.. such is the power of suggestion.  So even though prior to the yoga class this athlete had expressed how great they feel about how strong and flexible they had become through consistent cardio, strength, and flexibility exercise, they suddenly experienced some kind of amnesia and attributed all their gains to a single yoga class and dismissed their previous year of exercise.  Until I reminded them of all the gains they made.  This is how strong the power of suggestion is and how effective yoga marketers are at convincing people to believe impossible promises.

I'm not entirely impressed with the endless barrage of promises of the 'magic' of yoga.  Huge promise of hope and health, in fact, too good to be true, but where our health or performance is concerned, many of us are all too willing to believe whatever promise of super-duperness that comes along. Magical thinking appears to be a prerequisite for yoga.

Yoga is not the only way, the best way, or the fastest way to become flexible.

There is another reason many will do yoga: stress relief.

There are lot's of studies demonstrating that yoga can reduce the perception of stress.  OK, how about all the studies that show that a good nights sleep will also reduce stress?  How about the studies showing that any regular exercise reduces stress? How about studies showing that learning to be introspective and mindful also reduces and prevents stress?  What? Say it ain't so! You mean a person can learn to be emotionally calm and overcome reactionary tendencies without yoga?

Sure, studies do show that yoga can help manage stress.  It's a little shortsighted though to forget to mention that studies also show that any physical activity can reduce stress.. most more effectively than yoga, especially if you raise the intensity.

A runner I know told me they didn't have enough time to get to yoga recently and was feeling anxious about not getting their regular dose of stress relief.  I said, "why don't you simply do a bit of yoga at home?"  I followed that up by saying that running reduces stress as much or more than yoga does.

After they pondered that for a bit they replied, "I've been convincing myself the only way I could reduce stress was at a yoga class, but I don't need the class".  Exactly.  Yoga holds no patent on stress relief and certainly is not the most potent strategy to reduce stress.  Part of this runners stress was coming from the anxiety they experienced from not doing yoga.  How's that for irony?  They had the false impression that management of their stress had to come from yoga.  Their false belief limited their perceived options to deal with stress.  Again, the cult of yoga works it's way into peoples heads convincing them yoga has special, unique effects that you can't get anywhere else.  Once hooked, many people have great difficulty realizing that yoga really isn't all that it's portrayed to be.

Yoga does not stimulate an endorphin response more effectively than any other exercise, but it does produce an endorphin response. The point here is that the naturally expected adaptations of increased flexibility etc come from being active, but the yoga guru's obscure this reality and claim that it's yoga's specialness that delivers the goods. Historically, prior to us understanding what a dopamine response is, human beings will have still experienced the euphoric experience of dopamine release.  But back then, lacking modern comprehension of brains, psychology, and muscles, people would have speculated about extra normal causes for these feelings.  They will have imagined a cosmic alignment, a spirit causing you to feel a certain way. But this was born in peoples fertile imagination, not through evidence based, tested fact finding.  Getting better at exercise naturally improves the rewarding feeling.  I can see our ancient counterparts believing that ritualized movements were appeasing an imagined force, causing them to feel good.  They would not have known physical activity was causing neural and skeletal muscle adaptations, and emotionally stimulating psychological responses.

But today, we understand that we don't need dogmatic poses or rituals to effectively stimulate our brains to make us experience a euphoric or peaceful feeling.  We now understand that ancient humanity made mistakes in their conclusions.  We didn't need to meditate in a cave for years to achieve a more calm demeanour.  We now know that a few weeks of focussed compassionate thinking exercises will get this result.  But the ancient guru's didn't know that, and that's fair game, for back then.  Might not be so fair today to try and convince people that your Chakra needs alignment and that spiritual thinking will lift you to another plain and cure or prevent illness, because promising such things is fraud.  We now understand that those things aren't real, but were an uninformed way of explaining a natural phenomena that is simply part of human nature, explained by brain circuitry and neurotransmitters.

I can tell you that regular healthy physical activity can reduce the number of colds you get (by about 40% compared to sedentary), but this is explained by immune system and overall general physiologic adaptations to exercise and good recovery.  It would be wrong for me to tell you that I have a special diet, or special way of exercising that connects you with an immeasurable hidden power that can only be accessed with a certain way of thinking and moving.  I would be obfuscating the truth of your own physiology and convincing you that you needed to follow "my way" to get these benefits.  And, you want these benefits, don't you? That natural want can make us vulnerable to accepting the promise of hope, especially one that is elaborate and already has a lot of followers.

It's like a person doing a rain dance before a rain storm, then claiming their actions caused the rain, rather than the rain being a natural occurrence (we know how rain is part of the hydrological cycle. And we know how cells adapt to exercise).

One of my favorite studies on stress demonstrated that a mere 5 minutes of exercising in a green environment provided one of the best dose-reponses for exercise that reduced stress (5).

Any exercise can reduce stress, typically more intense exercise is better at releasing more of the hormones that make you feel good, and the more you do exercise (up to a certain point) the better your body gets at producing the hormones that make you feel good.  If you do yoga, which is physical activity, an endorphin response will occur.  It's not the "yoga", it's not spiritual, it's a natural response to exercise.  Don't fall for the bait and switch. This doesn't mean you give up those good feelings, you still get those good feelings of course, but instead of being misled as to their cause and origin, you'll know that this is your natural physiology.  You can get those feelings under your own power, anywhere you like.  They're yours to experience, not for a self aggrandizing, self anointed guru to give you.

How about the mindfulness that yoga can promote?  Yes, practicing compassionate and mindful thinking during yoga can help a person become more mindful.  But do you need to do yoga to do this?

An 8 week study on mindful thinking demonstrated that study participants who were directed to focus on non-judgmental thinking produced physical changes in their brains (6).  Grey matter density increased in areas of the hippocampus important for learning, compassion, and introspection.  Grey matter density decreased in the areas of the amygdala important for anxiety and stress.  Participants reported reductions in feeling of stress.

It's the physical function and distribution of grey matter density in your brain that are responsible for the changes, not a spiritual or cosmic or hidden inner energy.  So what's the problem with believing in hidden energy if you still get the benefit anyway?  You are mislead into believing falsehoods.  Falsehoods that you can become dependant on.  Falsehoods that divert you away from reality and prevent you from making informed decisions. You don't need to do a rain dance to water your garden.  You can irrigate it with your hose, because.. we know how to do that now (and we can do it so much better).

Regular practice of mindful thinking about being non-judmental and compassionate changes your brain so you become more effective at being non-judgmental and compassionate.  You can do this in a yoga class, or anywhere, anytime you like, and you don't have to be a monk or yoga master to do it (7).

When you practice non-judgemental and compassionate thinking, you are purposefully stimulating a natural adaptation in your brain.  Yoga people hijack this and tell you this is a spiritual awakening, or a manipulation of your inner energy, or some other euphemistic phrasing that sounds poetic and comforting. We are attracted to wanting to believe in these esoteric concepts and quick to dismiss reality.  It's common to not accept that reality is actually pretty good, and so to feel content we gravitate to utopian ideals and don't realize the deception.

You know that warm fuzzy feeling you get when you give and or receive a caring hug?  The hormone oxytocin is largely responsible for the perception of that feeling.  Knowing that doesn't diminish how good a hug feels, and doesn't make the good feeling go away. Interestingly, the more we know and appreciate someone, the more profound the hormonal response is. I think this is great!  But I know the warm fuzzies aren't due to energy fields aligning, that's nonsense.

If I found out that someone had BS'd me into believing these wonderful human feelings came from a cosmic energy alignment, but really it was normal human physiology, I wouldn't like that I had been mislead. I wouldn't like that I had been convinced to engage in special rituals in order to obtain and preserve how good a hug can feel.

I wouldn't like the fact that I had changed my thoughts, and behaviours, and invested my time and possibly money into this misleading scheme.

I might become disenfranchised with the person or people who acted like all that fluff was real, and who had indoctrinated me.  No this hasn't happened to me, but that's how I would feel. I have had people try though, and I didn't like it.  I have seen people get sucked in, and I don't like that either.

It's more empowering to know that how good I can feel is actually from my own doing, my own caring, compassion, and empathy (and my own pituitary gland), not from a ritual someone told me I have to do.

What about hot yoga?  Snake oil.  Many hot yoga purveyors will promise you that sweating in a hot yoga class will rid you of toxins that make you sick.

Apparently 'yoga sweat' is different than say, 'bicycle sweat'. Fat chance.  You can't sweat out toxins and net an anti-illness health benefit.  Body doesn't work that way. Sounds real special though, don't it?

Want to know one the biggest deceptions of hot yoga?  Sweat.  You can see it.  You're drenched in it.  Everyone is.  It's spectacle that draws your attention.  You can feel it.  You're immersed in it.  The instructor points it out to you.  You're promised you're going to sweat before the class, and the promise is fulfilled, so you feel gratified.  So what's the issue here?  You'll also sweat a lot riding your bike or going for a run on warm day, even more on a hot day.  Nothing special or unique is happening here.  It's like someone selling you air to breath.  You're already breathing air.

The way sweat works best to cool our body temperature is to have sweat evaporate.  When it evaporates it's gone.  So while we can certainly become wet with sweat while running and cycling, most of our sweat is evaporated by the airflow caused by our speed.  Sometimes, if the breeze is strong enough, you won't see much evidence of your sweat because it's evaporating at nearly the rate it's being produced.

Comparatively it will appear you can sweat much more in a hot yoga class, and anecdotally it can be difficult to refute this.

The hot yoga scam artist will use their rose peddled tongue to calmly indoctrinate you into believing you're sweating more, sweating in a special way, and becoming less ill and more healthy .. because you're sweating.  And hey, you KNOW you're sweating right? So they must be right.

What do you call a person that promises you that they have a special cure for what ails you, but really they don't?

One of the tenants of hot yoga is that the heat reduces the discomfort of pushing past your current range of flexibility.  Both instructors and students alike applaud this "benefit" and indeed comment on how much less it hurts.  That's a pretty big problem.  That discomfort is there for a reason; it's sensory feedback to tell you you're passing your safe limits.

It's important to be sensitive to your current limit of flexibly so you can progress your range of motion gradually, without stressing connective tissue too much.  The heat reduces pain, but your tissues are not instantaneously made stronger.  Connective tissue strength is still the same, but you're now at greater risk of surpassing that strength because you can't feel the warning signs of pain as well.

When you apply critical thinking, and look at factual evidence, it's easy to see that most of the health and fitness claims attached to yoga are either exaggerated, or complete nonsense.

An important factoid regarding adapting to exercising in a hot environment, like a hot yoga class.  Part of heat acclimatization involves a preservation of minerals lost in sweat.  The more you exercise in a hot environment the less salt will be excreted for the same amount of sweat.  The rate of everything that will be excreted, including the tiny trace amounts of potassium, calcium, iron, lead, lactate, will be reduced the more you do hot yoga.  So much for the promise of sweating out toxins.  In fact the exact opposite would occur; if toxins were released in sweat, hot yoga would decrease the release.  In reality it's your liver and kidneys that handle the extraction of toxins from our bodies.  Sweat glands, quite simply, are not a significant part of our bodies detox system.  Why don't hot yoga people tell you this?  You can't teach what you don't know.  But hey, sure sounds good to be told you'll sweat out toxins.  Makes the yoga instructor seem knowledgeable too.  Too bad it's all demagoguery though.

Here's a study showing reduced mineral loss in sweat though heat acclimation.

 http://www.ncbi.nlm.nih.gov/pubmed/18408609

Your liver is a multitasker, converting lactate into sugar to be used as energy, storring sugar, making proteins, making biochemicals for digestion, filtering toxins, and more

Your kidneys are also multitaskers, removing urea and ammonium from the blood, regulating blood pressure and pH balance, and producing hormones, and more

Your sweat glands main job is to cool the body.

If you're into yoga or considering it, consider the facts I present here, you may find that yoga isn't all it poses to be.

I like the fact I can throw my foot up on the counter or reach past my toes and give my hamstrings a good stretch all on my own.  That feels great. Most stretches can be done pretty much anywhere, any time, and produce the desired outcome if one learns how to stretch effectively (not being too aggressive, but going deep enough to feel a mild tightness, then holding until the tightness subsides. Then go a bit deeper and wait for tightness to subside again. Repeat tightness - wait until subsides cycle 3-5 X).

Comparatively yoga is no better than stretching for increasing flexibility (because yoga is stretching), is not a suitable replacement for aerobic exercise, isn't as challenging as strength training and wont make you as strong as strength training (or build and maintain muscle mass and bone density as well), and is not better at stress reduction than any other exercise, and finally yoga is not the best, or the only way to guide yourself to being more introspective or compassionate.

What about using yoga to augment what you're already doing?  Many athletes are being taken in by the promise of hope that yoga will improve recovery and flexibility.  Really?  Introducing proper recovery and stretching to those who don't do so regularly will decrease stress and increase performance.  If you affix a yoga label to these actions you're likely to convinced it was the enigma of yoga, rather than explainable adaptations to stretching and recovery. It's a reasoning fallibility called confirmation bias.

You can increase flexibility in yoga by doing the stretches (euphemistically called poses).  If your training load is lacking proper recovery and you replace some training with the lower workload of yoga, you'll recover more.  But it would not be yoga that is the cause of recovery or flexibility, it would be removing the extra training and adding stretching.  

Yoga is an option, and many enjoy it.  From what I've witnessed, many apply far too much benefit to yoga and have been taken in by the subdued pomp and circumstance, and the promise of hope.

There are many options open to all of us, many of which fall into the too good to be true category.

1) The metabolic cost of hatha yoga. [J Strength Cond Res. 2005] - PubMed - NCBI

2) Does practicing hatha yoga satisfy... [BMC Complement Altern Med. 2007] - PubMed - NCBI

3) A randomized trial comparing yoga, stretchin... [Arch Intern Med. 2011] - PubMed - NCBI

4) What is the Best Dose of Nature and Green Exercise for Improving Mental Health? A Multi-Study Analysis - Environmental Science & Technology (ACS Publications)

5) What is the Best Dose of Nature and Green Exercise for Improving Mental Health? A Multi-Study Analysis - Environmental Science & Technology (ACS Publications)

6) Mindfulness meditation training changes brain structure in eight weeks

7) Brief meditative exercise helps cognition