My students rarely complain, but when they do it's often about a lack of arm power. Over and over I hear, "What can I do to strengthen my upper arms? They feel so weak in Downward Dog, Chaturanga Dandasana, and Handstand!"
Fortunately, the answer is right on the mat. Many yoga poses help strengthen weak arms—and make strong arms stronger. A quick review of the anatomy of the upper arm and of some basic exercise physiology principles will show you how.
The major muscles of the upper arm are the biceps brachii and the triceps brachii. The biceps fills most of the space between the shoulder and elbow; if it's well developed, it forms a noticeable bulge on the front of your upper arm.
Biceps, which is Latin for "two heads," refers to the muscle's two sections; each has a tendon that attaches to the outer edge of the shoulder blade just above the shoulder joint. The other end of the biceps attaches to the radius, one of the two forearm bones, near the elbow.
You mainly use your biceps to bend your elbow, which you do dozens of times a day, whether you're lifting something heavy, bringing a cup to your mouth, or pulling on a dog's leash. You also use your biceps to help flex your shoulder when you lift your arm forward and then overhead. Finally, you use your biceps to help rotate your palm when you turn a doorknob or screwdriver.
The triceps sits at the back of the upper arm. As the name implies, the triceps has three heads. Two originate on the humerus, or upper arm bone, and one originates on the outer edge of the scapula, just above the shoulder socket. The other end of the triceps attaches to the ulna, the second of the two forearm bones. You mainly use your triceps to straighten your elbow—pushing a lawnmower or a heavy door or lifting yourself out of a chair by pressing into the armrests. The long head of the triceps also helps you perform shoulder extension, the position you use in Sarvangasana (Shoulderstand) and Setu Bandha Sarvangasana (Bridge Pose).
The biceps and triceps perform opposite actions at the elbow, often in conjunction with each other. Think of driving a car with a stick shift: The triceps pushes the shifter away from you, and the biceps helps pull it back.
In yoga poses, the two muscles often contract at the same time, stabilizing the elbow. You may be able to see or feel this in poses that require you to bear (and balance) weight on your arms, including Sirsasana (Headstand) and Pincha Mayurasana (Peacock Pose, also known as Forearm Balance).
Practice Builds Strength
If you struggle in Sun Salutations to move from Plank Pose to Chaturanga to Urdhva Mukha Svanasana (Upward-Facing Dog Pose), you may wonder whether you should lift weights to build strength. And if you choose to go that route, you might try an exercise called the triceps press: holding a dumbbell overhead, bending your elbow to bring the weight to the back of the shoulder blade, and then straightening the arm again. This exercise would certainly strengthen your triceps—but not in the exact way you need for Sun Salutations. Research shows that the best way to strengthen muscles for any activity is to work them in the precise position—and in the same pattern of teamwork with other muscles—the activity requires. To best build Plank-Chaturanga-Up-Dog strength, you have to closely mimic the positions and actions the poses require.
The same principle holds for building a different kind of triceps power called isometric strength. In isometric actions, the muscle works but doesn't change length, and the joint it's influencing doesn't change position. You need this kind of strength in many yoga poses that don't involve bending and straightening the elbow against weight resistance, including Downward Dog, Handstand, Sirsasana, and Pincha Mayurasana.
If you're already strong enough to practice the poses we've been discussing, the best ways to build power are through more repetitions and longer hold times. But if you're not strong enough for that yet, you should practice modified versions that come as close as possible to reproducing the action of the full pose.
Work with versions you can happily practice about three times a week. If a strengthening exercise or pose is too hard, frustrating, or painful, you probably won't practice it regularly enough to produce results. Practicing a strengthening move once a week doesn't build much strength.
Take a Chair
If your upper body is relatively weak, you can begin to condition your triceps isometrically by practicing a Downward Dog variation with your hands on the seat of an armless chair. Walk your feet back about three feet from the chair and push your hands into the chair, straightening your elbows, lengthening your spine, and pushing your hips back. (You'll probably feel some calf stretch, but you should be able to keep your heels on the floor.) Then lift your heels and move into Plank Pose, forming a straight line from your heels to your ears. Move back and forth between Downward Dog and Plank a few times. As you practice this over several weeks, aim to gradually build endurance until you can hold each pose for at least a minute.
You can work in this "Plank-on-a-Chair" position to build the strength you need for the Plank-Chaturanga-Upward Dog sequence. Keeping your elbows close to your sides, bend them just a few inches, then straighten them again. These mini yoga push-ups are much easier than the full version but will still prepare you for it.
Hold the Line
When you're strong enough, move to the floor for your Downward Dog to Plank transitions. Again gradually increase your hold times to build your isometric triceps strength. You can also practice mini yoga push-ups, and eventually full ones, from Plank position. In all this work, be sure to keep a straight line through your legs and torso, without sagging in the middle. If you can't hold the line, practice with your knees on the floor and create a straight line from your knees to your ears. When you practice with proper alignment, you target the muscles you want to strengthen. Otherwise, you recruit less anatomically optimal muscles to do the work.
By doing Downward Dogs, Planks, and push-ups a few times each week, you build strength in your triceps that will allow you to practice Sun Salutations and inversions with much greater ease.
While it's easy to use yoga to build triceps strength, building biceps strength is a different story. Biceps are very important in daily life, but they don't get much work in yoga, which doesn't include a lot of lifting or pulling. You may occasionally grasp your feet and bend your arms to pull yourself deeper into forward bends, or work your biceps in Headstand and Pincha Mayurasana. But that doesn't really constitute a strength workout for the biceps the way Sun Salutations do for the triceps.
If you want to do some biceps weight lifting to complement your yoga, start by purchasing a small hand weight (two to five pounds). Leave it by your phone and do a few lifts as you chat. Start with your arm down at your side; keeping the upper arm in the same position, bend your elbow to bring your hand up to your shoulder. Start with 10 repetitions, and gradually build to three or four sets of 10. After a while, you'll want to try a heavier weight.
Use It or Lose It
Through our first three or four or five decades, most of us take for granted the ability to lift, push, and pull objects as we interact with the world. But if you don't regularly challenge your strength in these activities, you tend to lose it. In my years of physical therapy practice, I've worked with many folks in the later decades of life who can't lift a bag of groceries, get themselves up off a chair, or push open a heavy door. The key to avoiding this fate is working those upper arm muscles regularly, at least a few times a week. Your reward will be strong muscles that help you progress in yoga and help you live actively and independently all through your life.
A licensed physical therapist and certified Iyengar Yoga teacher, Julie Gudmestad runs a private physical therapy practice and yoga studio in Portland, Oregon. She regrets that she cannot respond to correspondence or calls requesting personal health advice.