Ever wonder why yogis are strong but don’t have bulky muscles?


I did. My curiosity lead me to do some research and this is what I discovered. In yoga we spend a lot of time engaging our muscles isometrically as well as lengthening our muscles both actively and passively.

In technical terms these actions are called isometric muscle contractions, isometric stretching and passive stretching. These types of practices tone and lengthen our muscles and give us both the flexibility and strength we need to prepare for more advanced poses.

How to build strength and flexiblity

An isometric muscle contraction is when we activate a muscle, or group of muscles, without movement.The name isometric comes from greek and means “same length” as in the muscles don’t create movement though they are engaged.

This means that the muscle fibers contract but the actual muscle doesn’t shorten or lengthen because there’s no movement involved.

An example of this is when you take five breaths in down dog: your arms are pushing the floor away, your thighs move back, your core is engaged, yet you are not moving; you are activating your muscles isometrically.


The opposite of an isometric contraction is an isotonic contraction: in this type of muscle activation the muscle (or muscle group) alternatively shortens then lengthens as you move. It does this by switching from concentric to eccentric contractions.

An example of this is a classic sit-up. When you lift your shoulders off the floor you contract your abs concentrically and when you lower your shoulders back down you contract you abs eccentrically. The key to this contraction is movement. There’s no such thing as an isotonic stretch because stretching involves being still and isotonic contractions occur during movement.


Isotonic Contractions build and strengthen muscles but they also shorten them. In yoga you’ll find that isotonic contractions are offset with deep stretches so as to retain maximum flexibility.

Here’s two yogic stretches you’ll  love

Isometric stretching involves contracting a muscle that is held in a lengthened position using a prop (like your own hand or the floor). An example of this is – one of my favorites – quad streches! (see photo below). This pose stretches the quads and feels delicious!

To isometrically activate the quads you have to press your foot into your hand; hold here and take five deep breaths. Isometric stretching simultaneously lengthens and strengthens themuscle/s you are working. I love them!


Another type of stretch commonly practiced in yoga is called passive stretching. This is when you don’t actively do anything but instead let gravity, time and breath stretch and relax your muscles.

This may sound familiar if you’ve practiced Yin-Yoga or if you’ve been to a restorative yoga class. In both cases you hold the poses for longer and concentrate on consciously releasing tension in your body. Passive stretching is gentle and soothing; it also favors the healing of tight and/or overstrained muscles.


This concludes this month’s “Anatomy Highlights” series which will resume in October alongside the anatomy study group. If you’ve enjoyed reading I’d love to hear from you.

Also, please share on your favorite social media and with those who will enjoy it.

This article was written by
Julia Zatta

Julia is a yoga anatomy teacher and bodyworker based in Barcelona, Spain.

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