Hi Stemians! Thanks so much for your support on my last post about meditation! I'm hoping to get an article out every couple days. I'm thinking of doing coffee or exercise next. If you have a topic you'd like me to cover just let me know in the comments!
Yoga is an ancient Indian practice which seeks to enhance the physical, mental and spiritual abilities of its pupils. It is described in the Yoga Sutras of Patanjali as "the stilling of the changing states of the mind." I’m sure you’re all familiar with the beneficial effects so widely claimed by the practitioners of yoga, called yogis. It is estimated that there are over 20 million yogis in the US alone. That’s about 8.7 percent of the adult population.
With such wide spread use, it would be hard to believe that yoga is not beneficial in some way, and I doubt anyone would say it is not physically beneficial. But, what about the mental aspect? Will practicing yoga improve your cognitive abilities? I’m sure most yogis would answer this question with an astounding yes. After all, that is one of their core beliefs. Well, as it turns out, there have been a few scientifically controlled studies to better assess this claim.
As part of her doctoral dissertation at the University of Illinois at Urbana Champaign, Neha Gothe conducted a study on The effects of an 8-week yoga intervention on cognition and functional fitness in older adults. 118 individuals, mean age of 62, were split into two groups. The first group practiced Hatha yoga three times a week for 75 minutes involving postures, relaxation, breathing and meditation. The control group met on the same days and times, but followed an anaerobic stretching routine involving resistance bands. It was found that the yoga group experienced significant gains in cognitive performance over the control group.
“The 8-week yoga intervention improved executive functions including attention and information processing speed, working memory capacity, efficiency of mental set shifting and perceptual comparison speed.”
These findings were based on six standardized cognitive assessments conducted during the study. In addition to this, levels of cortisol in the saliva were recorded throughout. Cortisol is a steroid hormone released by the adrenal cortex in response to stress. It is commonly used as a marker for stress levels during scientific studies. As you may have guessed, cortisol levels were also shown to have decreased in the yoga group. This seems to support that yogis, as they have claimed, experience an overall decrease in stress.
While this study focused on the beneficial effects of yoga on older adults, Neha and her colleagues also conducted a study on college aged women. Additionally, this study examined acute twenty minute yoga sessions. You can find the implications of that study, brought to you by the writers of BoostedMemory, right here!
The cognitive benefits of acute yoga training
While the previous study focused on the beneficial effects of yoga on older adults, Neha and her colleagues also conducted a study on college-aged women. Additionally, this study examined the effect of acute 20-minute yoga sessions as opposed to the benefits experienced over an 8-week period. This is important because it gives better insight as to the state of mind experienced during yoga practice.
There is a good deal of evidence supporting cognitive benefits gained after acute cardiovascular exercise, but these studies do not take into account the mind-body components of yoga which likely also affect physical and mental processes. Yoga is a multifaceted activity, and all aspects should be explored.
Thirty undergraduate women who did not regularly practice yoga or any other mind-body based exercises were recruited for participation in this study. Their cognitive functioning levels were analyzed to assess baseline working memory and attention levels. In addition, baseline physical fitness levels were also determined.
The women were asked to participate in two different experimental protocols involving a condition followed by cognitive evaluation, each on a separate day. The conditions were either a twenty-minute Hatha yoga routine, or a twenty-minute run on a treadmill. The yoga routine consisted of nine poses using standing, seated and supine postures. The treadmill run allowed for a self-selected speed and incline, which kept the participants heart rate at sixty to seventy percent of their estimated max heart rate. This range was chosen to replicate previous findings of improved cognitive performance. (I plan to write a post on the cognitive benefits of exercise soon!) Cognitive testing took place three to six minutes after the condition.
“The current findings indicated that the reaction times were shorter and the accuracy was significantly greater after an acute bout of yoga for tasks requiring greater amounts of executive control, indicating improvements in inhibition and working memory. In contrast to previous research, similar effects were not observed after an acute aerobic exercise bout at 60%–70% of HRmax”
However, I cannot completely agree with these findings. I do not argue against the improvements seen in the yoga trial, but on the relative comparison between yoga and aerobic exercise, there is a confounding variable. Because the cognitive tests were performed three to six minutes after exercise, the participant would still be fatigued following a run in which their heart rates were at an average 155 BPM. This is an incongruent comparison to the yoga routine in which the average heart rate was only 78 BMP, resting heart rate. Previous studies, in which there was a longer interim between exercise and testing, revealed a greater cognitive benefit from aerobic exercise than was seen in this study. *This doesn’t take away from the beneficial effects of yoga, as the comparisons were made to baseline assessments.
Though more studies will need to be conducted to further elucidate the cognitive benefits gained from acute yoga exercise, the preliminary research does seem promising. Real memory improvements are seen in those who practice yoga. Possibly a partial mechanism to this improvement, decreased stress levels are also found in yogis. This is a huge benefit in the stressful life of the modern world, and is why yoga would benefit anyone who dedicates the time to practice. Perhaps you shouldn’t completely substitute yoga for aerobic exercise, but the two in combination would be a potent enhancer for anyone looking to improve their memory and cognitive abilities.
A great way to get into yoga is to follow along with youtube (or Dtube!) videos. I really enjoy Yoga with Adriene on youtube, but there are also some Stemians posting yoga videos that could possibly provide a similar service. You should check out 
Sources:
Gothe, Neha. University of Illinois at Urbana-Champaign, Department of Kinesiology & Community Health. Ph.D. Dissertation. 05-24-2013. http://hdl.handle.net/2142/44393
Photo credit: Alliance Russe on Flickr Creative Commons Attribution License (CC BY 2.0)