How many calories do you burn practicing yoga?

Probably not as many as you think.  Does that really matter?  Maybe not as much as you think. Students occasionally ask me “How many calories do you burn practicing yoga?” I often assume that what’s underlying the question is another question, “Will I lose weight practicing yoga?” but that’s really a different question, which I’ll…

Up dog on bridge

How does stretching make you more flexible?

How does stretching make you more flexible? Intuitively, it seems that it must have something to do with your muscles—that they must lengthen or that the tissue must become more pliable over time. Yet, as we’ve seen, the evidence doesn’t bear that out. Stretching makes muscle tissue more pliable in the short term, but those…

Headstand on beach

Do yoga inversions help drain lymph?

Do yoga inversions help drain lymph? Basically, yes. In the same way that inversions, such as headstand and shoulder stand, help return blood to your heart, turning upside down can assist lymph drainage from your legs. However, it isn’t necessary to invert to keep lymph moving. Your body has other means to accomplish the same…

Do yoga inversions reverse the flow of blood?

Do yoga inversions reverse the flow of blood? Although yoga teachers sometimes say this, the answer is no. The blood in your body only flows in one direction. From your heart’s left ventricle, it’s pumped through a network of arteries to the capillary beds that surround the cells of your body. That’s where your cells take…

What happens when you stretch a muscle? (Part 2)

In the previous post in this series, I described how stretching temporarily affects muscle tissue. This segment begins a discussion of long-term changes in flexibility. Ultimately, lasting gains in flexibility have more to do with your nervous system than with your muscles. More on that in the next post, but first, let’s look at an alternative hypothesis, namely…

Hanumanasana

What happens when you stretch a muscle? (part 1)

  “What happens when a muscle stretches?” This frequently asked question — a perennial query during anatomy trainings — deserves a few blog posts, especially as the mechanism is often misunderstood. Stretching targets muscles in two ways. First, it directly affects muscle and connective tissue itself. As you’ll see in this post, those effects are temporary and short-lived.  Stretching…

Research review: The effects of bhastrika in the elderly, part 3

In my last post about this study (1), I described how four months of pranayama practice affected respiratory function in elderly yoga practitioners. Today, we take a look at how the practice of bhastrika impacted heart rate variability and the functioning of the autonomic nervous system. Before delving into heart rate variability, a review of the autonomic nervous system is in order. The autonomic nervous system…

Research review: The effects of bhastrika in the elderly, part 2

To refresh your memory from the previous post, researchers in Brazil studied the effects of bhastrika practice in elderly individuals (1). They tested several measures of respiratory function at the beginning of the study and again after four months of training. Those measures included forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and maximum expiratory and inspiratory pressures (PEmax, or…