Yoga: A Critical Look

Yoga is a commonly-practiced activity, with lots of claims about its benefits. But how many of those benefits hold up to scientific scrutiny? And how do those benefits compare to the “gold standard” ways of achieving those benefits. For instance, the “gold standard” in improving strength is (obviously) strength training. The “gold standard” in improving endurance is cardio. How does yoga compare to the “gold standard” in each of those categories (and others)? That’s what we’ll examine in this article. After all, we don’t want to just answer the question of “does it work?” we also want to know “is it superior?”

Now granted, there are lots of different kinds of yoga, from hatha, to ashtanga, to yin, and others. Often the research looks at all of them together, but where the research differentiates or focuses on a specific type, I’ll state it in this article.

Ready? Let’s go.

Original source: here.

Does Yoga Improve Strength?

It’s unquestionable that yoga improves strength. It absolutely does. In one 6-month study, 80 sedentary, middle-aged women participated in hatha yoga 3 times per week for an hour. At the end:

• Their quad strength improved by 14.6%.
• Their biceps improved by 13.1%.

 

Another study showed pretty similar results. In this study, 22 sedentary women with an average age of 62 did yoga 3 times per week for an hour. After 2 months:

• Their quad strength improved by 11%.
• Their hamstrings strength improved by 41%.

 

But in both of these studies, the subjects were sedentary people. It’s extremely easy to show progress in sedentary people. It doesn’t require any skill, finesse, or attention to detail. In sedentary people, even going for a walk will strengthen the legs, even though it’s not strength training. It’s more impressive to improve the strength in people who are already active. So by how much does yoga improve strength in already-active people? By a disappointing amount.

In one study, active women between the ages of 35-55 did Ashtanga yoga twice a week for an hour, for 8 months.

At the end of the study, their strength improved by 11.4%. Womp womp.

Not great.

Let’s compare yoga to the gold standard for strength improvements – strength training. In this case, there’s no comparison. From my own data with clients (and remember who my clients are – mostly individuals over 50, including some over 80):

• Previously sedentary people improve their strength by 30-50% in a 6-month period.
• Previously active people improve their strength by 20-30% in a 6-month period.

 

And this is with training frequencies of about twice a week. Not a lot of our clients strength train 3 times per week.

In conclusion, yoga is OK for strength – better than being sedentary, and better than a lot of other activities, like strolling, hiking, etc. But it’s a far cry from the magnitude of improvement you see with strength training.

 

Core Strength

Whenever I hear anyone talk about core strength, it drives me nuts. Mostly because the majority of people have no clue what it is. They use the words “core” and “abdominals” interchangeably. They just want to sound fancy, so they use the word “core.” But the abdominals are only one fifth of the core. The core is really a cylinder. At the top is the diaphragm, at the bottom is the pelvic floor, at the front at the abdominals, at the back are spinal extensors, and on the sides, it’s obliques. Got it? OK, so stop calling the abdominals “core”, when you really just mean abdominals. If you’d like to educate yourself further, check out my article on core strength myths.

Anyways, to evaluate core strength, we must measure core strength. How do we do it? There are a few different ways:

• Plank
• Side plank
• Back extension
• Situps
• Lying leg raises

 

Sure enough, since the first 3 are poses/asanas directly practiced in yoga, it’s no surprise that indeed, core strength improves pretty well in yoga.

There, it’s pretty much on par with the gold standard, although you don’t necessarily need to do yoga to get the same benefits. Just do some core exercises, and they’ll accomplish the same goal. But if yoga is your shtick, and you’re already doing it, there’s probably no need to do anything outside of your yoga practice.

Although if someone tells me that they want to improve their core strength, I always wonder what for. After all, it’s rarely for the intellectual knowledge that your core is strong. It’s usually for one of 2 major reasons:

1. Back pain reduction.
2. They don’t want to appear vain, so they say they want to strengthen their core, when what they really want is to lose belly fat (nothing wrong with that, of course).

 

Does having a strong core reduce lower back pain? Sometimes. And sometimes it doesn’t. But to assume that 100% of cases of lower back pain are due to a weak core would be a giant mistake. I wrote a much more detailed article on lower back pain here.

As for fat loss, a strong core is not necessarily a lean core. In fact, many of the world’s strongest people have giant guts. There’s no relationship between strength and body fat. There are lean people who are strong (an example would be a prime Arnold Schwarzenegger), and fat people who are strong (my older readers might remember a 1970s Soviet weightlifter named “Vasily Alexeyev.” If you don’t know him, check out the picture below. I rest my case).

Original source: here.

            So if your reasons for having a strong core are either back pain reduction or fat loss, there are better ways to get it done than yoga. Not that you shouldn’t do yoga, just that it’s not the most effective way to do it.

 

Does Yoga Improve Endurance?

Having good cardiovascular endurance is one of the most important things you can have to improve both the quality and the quantity of your life. Does yoga help improve cardiovascular endurance? Let’s look at the research:

In one study, 173 people with an average age of 52 did yoga approximately 165 minutes per week. After 3 months, the men improved their endurance by 7.9%. The women improved by 5%.

An improvement of 5-7.9% is not very meaningful in “real life” terms (helping you not be out of breath when you climb stairs, etc.). By contrast, the gold standard for endurance is cardio. Cardio has the potential to improve endurance by 25-30% over the same time span, and possibly, in less time per week.

Of course, the variability in how much yoga improves endurance is very wide. I would venture to say that something like yin yoga (where you hold a single pose for 15+ minutes) doesn’t improve endurance at all, and a “high intensity” yoga (like ashtanga) probably increases endurance more than 7% (although likely not as much as cardio). With hatha yoga being somewhere in the middle (like 5-8%).

 

Does Yoga Improve Flexibility?

This one is where yoga really shines. The most common association is between yoga and flexibility.

There’s no question that yoga improves flexibility. Really well. Better than almost everything else. But the operative word is “almost.”

Because there is something that improves flexibility better than yoga. The gold standard for flexibility improvements is a method of training called PNF (proprioceptive neuromuscular facilitation). Also called “contract-relax stretching.” Here’s a video showing what PNF stretching looks like.

There’s no comparison.

• What you need: 30-90 seconds per muscle (and not every muscle needs to be stretched).
• Frequency: 2-3 times per week.
• And you basically normalize range of motion within 1-8 sessions. To maintain the newly-found range of motion takes a lot less work than to improve range of motion. All you need is to repeat that exercise approximately once very 1-3 months, and you can hold on to your new flexibility almost indefinitely. One systematic review even found that with PNF, even if you stop for 4-8 weeks, you maintain all your flexibility.

 

So if the only thing you want to get out of yoga is flexibility benefits, but you’re agnostic as to which tool gets the job done, PNF is far superior, and faster. But if you like yoga for its own sake, you can’t go wrong with that either.

Though if you broaden your perspective, and ask why you want to improve your flexibility in the first place, that would be a better question. I’ve written extensively about flexibility/stretching myths here, here and here.

 

Does Yoga Improve Balance?

Another common reason people turn to yoga is to improve their balance. Does it work? Absolutely. Lots of research shows that it does.

Is it the best form of balance training? It’s a good form, but not the best. In one study, 39 people with an average age of 74 were divided into 3 groups:

• Group 1: yoga
• Group 2: tai chi
• Group 3: standard balance training (similar to what I demonstrate in this video)

All 3 groups trained for 1 hour, twice per week, for 12 weeks. The improvements were pretty similar in all 3 groups, with slight differences:

 

• The tai chi group had slightly better results in side-to-side balance, when trying to stay still.
• The standard balance training group had slightly better results while moving.

 

So yoga might not be the best, but is certainly in the upper echelon of methods for balance training. However, none of those are the gold standard when it comes to balance training. The gold standard is something called “perturbation training.” That is, perturbation training is very specific to trips, falls and slips. Here’s a short video detailing what it looks like.

In yoga, the goal is to prevent yourself from losing your balance. In other words, you expect to be off balance, so you focus on maintaining it. Whereas in perturbation training, you lose balance on purpose (a training partner pushes you off balance, without you knowing in which direction) in a safe, controlled environment, so you train the body to “catch itself” when balance is lost.

There aren’t any studies that directly compare yoga to perturbation training, but there are studies comparing perturbation training to tai chi. Since in the previous study, yoga and tai chi improved balance to a similar extent, we can use tai chi as a proxy for yoga as well.

In one study, 35 people over 70 were divided into 2 groups:

• Group 1: perturbation training
• Group 2: tai chi

 

Both groups trained for 30 minutes, 3 times per week for 4 weeks. Across every measure, perturbation training was superior to tai chi (and again, by extension, yoga):

 

• Amount of training: in this study, the tai chi group didn’t improve their balance at all. Why did balance improve in other studies but not in this one? A big reason is that the studies that show balance improvements from tai chi have people training 3-7 times per week for 50-60 minutes. Here, they trained 3 times per week for 30 minutes.
• Magnitude of results: in this study, falls were not directly measured, but other balance tests were given. However, one study showed a 50% reduction in falls from just a single session of perturbation training. To show you that I’m not cherry-picking my research, an entire meta-analysis found a 46% reduction in falls from perturbation training.
• Speed of results: the tai chi group didn’t see any results (for reasons we talked about earlier). In this study, the perturbation training group saw results in just a single week. In the other study I mentioned, they saw results (large ones) in just a single session.
• Durability: what happens after you stop training? Hopefully, you never stop, but if you do, how fast do the results go away? With tai chi, pretty fast. With perturbation training, they last and last and last. Like the energizer bunny. In this study, 6 months after perturbation training was stopped, their balance was still maintained.

 

I’m not aware of any other training method where after a single session or a single week you have such dramatic improvements in anything. To get a 50% improvement in strength from strength training requires 6-15 months. A 50% improvement in cardio almost never happens, because cardio can only improve by about 30%. But with perturbation training, both the magnitude and speed are very high.

 

Conclusion

In conclusion, if you’re looking for maximal effectiveness in any fitness quality (strength, endurance, flexibility, balance), yoga is not your best bet. But, if you’re just doing yoga because you enjoy yoga, that’s time far better spent than sitting on the couch.

For example, I did martial arts for 12 years, because I really, really liked it. It improved endurance and flexibility really well. Strength improved modestly, and balance improved a little bit. Nonetheless, it was fun. I didn’t do it for fitness (that was a side benefit, and I could get far better results by doing dedicated training outside of martial arts), but for fun (and competition/tournaments).