Alternative medicine advice on hydration from a yoga instructor

Question

After yoga class yesterday, my instructor complained to me that I was burping too much in class. She saw a sparkling water bottle, which actually had tap water in it, and she assumed I was drinking sparkling water during class. In fact, this is a longstanding issue for which I've unsuccessfully sought medical help.

Nevertheless, she recommended that I drink less water during class. From everything I can tell, that is bad advice. By email, she offered a rationale from ayurvedic alternative medicine:

The main reason being what’s known as agni (the digestive fire); we stoke that fire through the course of practice- which is why yoga is generally helpful in jumpstarting the systems of the body- it wakes up both appetite and sluggish digestion and more. There is a big process of digestion during yoga practice as Agni also refers to the digestion of thoughts, emotions, experiences. So drinking large amounts of water “douses” the fire of both physical digestion and breaks the thread of concentration that we try to cultivate during yoga.

To be blunt (which I wasn't with my instructor), this sounds like quackery to me. Nevertheless, I am wondering if I should place my trust in her advice? For one thing, maybe she knows what she's talking about more than I give her credit for. (I don't know what happens during yoga teacher training.)

There's also the matter that I've otherwise enjoyed her yoga classes, and I fear that a teacher-student relationship is untenable if I don't trust her advice.

Answer 1

Disclaimer: I am not a professional of any kind in this or any related field. I am not in fantastic shape, either. All I can really say for my cred is that I exercise regularly and I've completed a handful of races without dying.

For the purposes of this Q&A, I am going to assume that the reason this sounds like quackery is because you are interested in practicing yoga exercise, but not Yoga philosophy. (Just trying to stay as neutral as possible here — I'm not into the philosophy either.)

Although yoga as an exercise program can of course be secular, a lot of the justifications for certain practices within it are still at least loosely related to the mystic tradition(s) from which it originates. Even if the reasons given for certain things sound a bit goofy, the practices themselves (motions, breathing patterns, etc.) seem to work. Since you're enrolled in the class and you're enjoying it, you probably don't need much further convincing, but this seems like as good a place as any to point out that wide survey results and at least a handful of Web-searchable studies indicate with reasonable confidence that yoga seems to improve overall health in various ways. If yoga can get the right answer for the wrong reasons when it comes to exercise, why not hydration?

But wait, we can do better than "why not". Articles like this one cite actual evidence that hydration during exercise is over-hyped:

There’s never been a case of a runner dying of dehydration on a marathon course, but since 1993, at least five marathoners have died from hyponatremia they developed during a race... German researchers similarly took blood samples from more than a thousand finishers of the Ironman European Championship over multiple years and found that 10.6 percent of them had hyponatremia.

And it provides a non-quacky-sounding justification:

When you sweat, your brain senses the corresponding rise in plasma osmolality and directs the release of antidiuretic hormone (ADH), which prods the kidneys to activate aquaporins... As your body reabsorbs water, your plasma osmolality returns to normal, your brain senses the change, and it shuts down ADH. This feedback loop is finely tuned to keep plasma osmolality in a safe range.

What I find sort of interesting here is that if you ignore the stuff about "digesting emotions" from your instructor's description of agni, it begins to look, in a magic-eye sort of way, at least a little bit like this researcher's explanation: drinking water during exercise interrupts the water-retaining process your body has naturally started, and, in the case of over-hydration, shifts it into a diuretic mode instead in an effort to lose the excess water.

Personally (anecdotally), I find that if I drink 1 glass of water in the morning and head straight to the gym, that's plenty; if I go in the evening after work instead, 3 glasses of water throughout the day are also plenty. The usual routine is 35 minutes jogging/running various speeds on a treadmill, then one sip of water from a fountain, then 35-45 minutes of weight-lifting. The "eight glasses of water" rule I keep hearing about is at least twice as much as I ever realistically drink (unless you count a mug of black coffee as though it were 3 glasses of water, which seems wrong on many levels).

Answer 2

What your instructor is saying is quackery. However, why not make her happy? You might not need to drink water during the class. I think there is a bit of paranoia about hydrating that says you need to constantly be drinking water, and I'm not sure there is scientific evidence for this. I do an hour and ten minute weight lifting workout without drinking water and I never have a problem. I find drinking water slows me down. I start gradually hydrating a few hours before my workout, so I go into the workout appropriately hydrated when I start. Do you think you can figure out how to do the class without drinking water? Here are two caveats: if the room is hot and you are sweating profusely, then that is a different matter. Second, if the class is an hour and a half, then in my experience that starts to get close to the point where water is required. Maybe you can wait until an hour and fifteen minutes in before you drink. Would you burp then?

Answer 3

Anytime someone quotes Ayurvedic alternative medicine, it should instantly raise your spider sense. There are yoga instructors that have a good grounding science/reality but there are also plenty that just regurgitate the dumb crap they learn in their certifications.

Your instructors justification is horseshit but maybe they are just hoping to convince you to stop drinking, so you stop burping, and they don't really care about the rationale. I wouldn't blame them, burping all the time can be a distraction to the class.

That being said, plenty of people over-hydrate and don't need to be drinking as much water as they think they do. It's something the media has been overhyping for years:

Fluids, Hydration and Fitness

However, you burping in class all the time is likely the real issue for your instructor. Sounds like they'd just prefer you not to be burping all the time, and by not drinking, hopefully that gets accomplished.

The simple thing to do is make sure you're hydrated going into class. Then rather than sipping all class, simply weigh yourself after yoga and consume the amount of water that you lost. You're not going to put yourself in any great risk by doing this.

If your exercise isn't lasting longer than 60-90 minutes and it isn't that high intensity, you likely don't need to be drinking water during yoga. Unless it's a very hot room and you're sweating buckets (in which case, pick an interval sequence to reduce burping for your classmates sake, i.e. every 10 minutes, or every 15, or every 20).

Dehydration does reduce performance, but that's more relevant to high intensity exercise, as opposed to yoga. There is a very simple easy way for you to assess your hydration levels:

Look at your urine. If it's off-clear, with a slight yellow hue to it. You're hydrated. Be that way going into yoga.

If you can't weigh yourself soon after yoga (1 kg lost = 1 liter to drink), then simply look at your urine again. If it's yellow, you need to drink more than usual. If it's dark yellow, double that.

There's also the matter that I've otherwise enjoyed her yoga classes, and I fear that a teacher-student relationship is untenable if I don't trust her advice.

Having a healthy skepticism is different from a lack of trust. She's a yoga instructor, not a dietician, so trust her when it comes to yoga.

If you're medical doctor gave you advice on your pet, would you take it, just because they are a doctor? What the hell do they know about your pet? They aren't a vet.

Same thing here...nutrition, isn't your yoga instructors scope of practice really.

Answer 4

In yoga meta-physiology, burping is controlled by a specific prana, one of five major ones. An excess of burping would be considered an imbalance of the prana controlling that specific bodily function. Yoga practices, when presented in a balanced manner, would balance the five mjor pranas in the body resulting in overall health and possible addressing of the excessive burping.

Aside from extreme aerobic yoga sessions, I've never been in or taught (in last twenty years) a class that requires students to drink water during an hour and a half class, of which 40-60 minutes are dedicated to asanas, 10-20 minutes to pranayama, and the remainder to relaxation and or preparatory meditation practices.

Having suffered from constipation on and off during my early life, I did try to drink a lot of water as a remedy, but had mixed results. When I came across an ayurvedic suggestion to refrain from drinking water an hour before meals and an hour after meals, I noticed positive changes in my digestion. The suggestion relates to what your yoga teacher cited about the digestive fire. Drinking water is also a process more than just swallowing. I read in a yoga book once that water should be eaten and food should be drink. It highlights the awareness with which we take elements into our body such that the body can actually integrate them rather than passing them straight through.

Yoga is a science. You don't have to trust anyone's advice. Try it; test the claim. See if it is repeatable. If it brings sustainable, positive changes, integrate it into your lifestyle. If not, share that feedback with your teacher.