You've heard the phrase, "Use it or lose it."
Think of a car that isn't driven for months. When you go out to start it, the battery has died. The oil in the crankshaft is gunky. It's starting to corrode.

Now imagine your body is that car. Left idle too long and we begin to get stiff. We lose our strength. We might even start to "corrode" on the inside!
In order to maintain our health, our bodies need to move. And the advantages of keeping moving are many:
- it builds strong bones
- it encourages cardiovascular and respiratory health
- it alleviates depression
- it lets us maintain our independence
Believe it or not, we begin to lose muscle mass at around age 30. If we haven't made exercise a habit by the time we're in our 50s or so, we're setting ourselves up for trouble later on. One of the reasons people find themselves in nursing homes is because they can't take care of themselves. They don't have the strength to get up off a toilet unassisted or in and out of bed.
We lose bone density as we age and that can weaken us as well. This leaves us more vulnerable to falls, which can lead us down a path of broken bones and time spent in nursing homes and rehab centers.
But can yoga really make us stronger?
Yes, with a regular practice and keeping the information below in mind.
You build strength either through isometric muscle contraction or resistance training.
Using static poses to build strength
Holding a pose is an isometric move. But standing in Warrior II with your arms outstretched isn't really an isometric muscle contraction on its own. You must add in conscious muscle activation. To do this, first relax the muscle, allowing it to lengthen. Then gently firm the muscle to the bone.
Taking the example of Warrior II above, relax your arm muscles, feel them lengthen. Then, without using a strong contraction, pull the bicep and tricep to the bone. If you're in a bone-strengthening pose such as Downward Facing Dog, you can firm all the surrounding muscles around the bone as well. In this example, you'd firm all your arm muscles and shoulder muscles toward the bone. When you want to strengthen your hip area, in a standing pose, for example, you can slowly engage the muscles all around your hip joints, ensuring that this action does not pull you out of good alignment.
How long to hold the pose? For muscle strength in static poses, you can either work on muscle strength or endurance. To work on muscle strength alone, hold the pose at least 8 to 10 seconds and consider repeating the pose several times. To work on endurance, hold the pose as long as you safely can, gradually working up to 1-2 minutes or longer.
Resistance training for strength
We're all familiar with resistance training for our muscles. We see bodybuilders lift weights or people in the gym using resistance bands and other equipment. You can do a lot with just your body weight. Think of a vinyasa flow such as inhaling to Downward Facing Dog, exhaling to Plank.
Here, you're "resisting" against the floor to build muscle as well as putting your muscles through a range of motion as you get into and out of the pose. This is very different than just holding a pose for the same length of time.
What about our bones?
A few words about how static and dynamic poses help our bones, because as noted above, bone density also decreases with age and can also lead to a stint in a nursing home.
For bone strength, holding a static pose (i.e, Vrikasana or Tree) for 30 seconds or more has been proved to be effective. For bone strength in dynamic poses, based on what is known about weight-bearing movement such as walking and running, practicing poses dynamically in sets of six repetitions is recommended.
Which one should I do?
Neither is better; doing both is best. A well-rounded practice will include both static and dynamic muscle training for building both bone and muscle strength.
Several Yoga for Health Aging blogs were a basis of this article. The blog is written by Nina Zolotow, RYT-500 and Baxter Bell, MD, eRYT-500.