|Hours of Operation by Melina Meza|
In his own attempt to answer the question, he cited an April, 2013 article in an issue of Prevention Magazine which claimed, referring to a study done in postmenopausal women, that 42 minutes of vigorous exercise over 3 days (that means 14 minutes a day) maintains telomeres. As regular readers of this blog will know, telomeres are little “caps” or tails on the end of DNA stands that may have a relationship to longevity of certain cells in the body. Recent yoga studies have shown a positive relationship between yoga and telomere length. However, I don’t think the yoga practices in these yoga studies were only 14 minutes long, and likely would not fall into the category of “vigorous exercise.” However, this is an intriguing idea, and I’d say if you could hit the 14-minute mark in your home practice, that is a good start—more on that in a minute.
My student also cited “100 New Scientific Discoveries” issue of Time magazine, where he came across this:
“Researchers [in Stockholm] say that even a single 20 minute workout can lead to epigenetic changes that help make muscles work better.”
For those not familiar with the field of study known as “epigenetics,” I offer this Wikipedia definition:
“epigenetics is the study of mitotically or meiotically heritable changes in gene expression or cellular phenotype, caused by mechanisms other than changes in the underlying DNA sequence—hence the name epi- (Greek: επί- over, above, outer) -genetics.”
In this case, exercise is influencing how the genes of muscles express themselves leading to improved muscle function. I’ll take it! And 20 minutes sounds even better to me than 14 minutes for a home yoga practice.
And real life examples of the power of a regular practice are equally compelling to me as scientific studies. Recently, a long-time student of mine who has chronic back pain experienced a distinct change in his daily health. In the past, he had come to my back care yoga class regularly, but eventually found that some of the poses we did would actually flare his chronic back pain. So we met privately and developed a home practice he could do for 15-25 minutes daily, if he so chose. He found that he would do the practice 2-3 times a week, and it helped his overall back pain nicely.
But then two months ago, he asked if we could audio record a practice that lasted about 40 minutes. He explained that his partner had become interested in doing some yoga at home and wanted something they could do together in the morning before work. We came up with a balanced routine that included poses beneficial for back health, but also breathing practices and a good Savasana at the end. When he returned for a follow-up recently, it was not the lower back symptoms he reported on, but that the chronic loose bowel movements he has suffered with every morning for years had diminished and stopped, replaced by a normal movement each am. He was thrilled and felt it was a direct effect of his new daily morning practice. And for him, 40 minutes a day works just fine.
We know from the work of cardiologist Herbert Benson, that 10 minutes of meditation is the time frame for the body to shift to the Relaxation Response (the Rest and Digest side of the autonomic nervous system), and by 20 minutes the effects are even more profound. And, of course, there are many other variables to consider when you design your home practice, as you can see from the 24 posts we have done to date that address the topic of home practice. We know, for example, that one study showed that it was regular home practice, more than attending classes over time or regularly, that seems to relate to long term health benefits of yoga (see Does Home Yoga Practice Make You Healthier? and Home Practice: The Best Way to Improve Your Health and Well-Being).
But like most issues we have discussed here over the years, the answer to this question of the optimal minimum time for home practice is really “It depends!” But, given what my astute student has uncovered, as well as research findings on the benefits of regular practice, my observations of my students and my own practice, I’d feel comfortable recommending that you try to hit that 20 minute mark, and on days when you feel like going longer, there is nothing to stop you!