50
february 2016yogajournal.comthe actin strands slide between the myosin
fi laments and the muscle shortens—in
this case, pulling up your forearm.
A similar thing happens during an iso-
metric contraction, except the force gener-
ated by the myosin cross-bridges exactly
matches the opposing resistance, so there
is no movement and your arm stays fi xed.
And, if the resistance is greater than
the force the muscle generates, such as
what happens to the biceps when lowering
from a pull-up, the biceps muscle will be
stretched, producing an eccentric contrac-
tion that allows your arm to lengthen with
control. Scientists don’t yet fully under-
stand this process, but it appears that dur-
ing an eccentric contraction, some myosin
cross-bridges continue to latch onto actin
fi laments, while others are pulled apart.
Perhaps surprisingly, muscles generate
more force eccentrically than concentri-
cally, meaning you can lower a heavier
weight than you can lift. You can use this
principle to build strength by focusing on
lowering movements. For instance, con-
trolling the descent from Plank Pose to
Chaturanga will eccentrically contract
and strengthen your triceps, while push-
ing back up to Plank is a concentric
contraction of your triceps.
Because eccentric contractions produce
more force than concentric ones, they also
put more stress on muscles. If you’re not
used to it, eccentric exercise can damage
muscle proteins, triggering delayed-onset
muscle soreness, or DOMS—usually at its
worst one to two days after a tough work-
out. While DOMS may be annoying, it
is rarely serious. Your muscles adapt by
becoming stronger after a bout of DOMS
so that the next time you do the same
routine, you’re less likely to be sore.
Another caveat about eccentric exer-
cise: It may also stress tendons, the con-
nective tissue that binds muscles to bones.
Repeatedly overloading your tendons in
this way without allowing for recovery
increases your risk of tendon damage, or
tendinopathy, a painful condition that can
interfere with your practice. Due to their
slow metabolic rate, tendons recover grad-
ually; once tendinopathy develops, it can
take months for full recovery.
But that doesn’t mean you should avoid
eccentric exercise. In fact, strengthening
your muscles eccentrically will help buildstronger, more resilient muscles and ten-
dons that are less likely to get injured in
the future—as long as you allow them to
adapt slowly. In fact, physical therapists
frequently use eccentric exercises to rehab
injured tendons.
Exploring the entry into Side Crane
Pose (above) will help you understand
how to use eccentric contractions wisely
in your yoga practice.continued from page 48ANATOMY
practice well
The transition into an arm balance like Side Crane Pose can be scary. There is a very
real risk of falling onto your head, given that one arm is supporting most of your
weight. Eccentrically engaging your triceps will allow you to come into the pose
safely and with control, avoiding a painful face plant.Squat with your feet and knees together, then twist your upper body to the right,
bringing your left upper arm against the outside of your right knee. Place your
hands on the floor alongside your right thigh, shoulder-width apart. As you shift
your weight forward onto your hands, lift your feet. Imagine that you are pressing
the floor away with your hands. This will keep your triceps eccentrically engaged
as your elbows bend, controlling how far your head lowers toward the floor.When you find your balance, your triceps muscles will work isometrically to keep
you there. However, at the sweet spot where your upper and lower body exactly
counterweight each other—like the two arms of a scale—your triceps won’t need
to do much. If you sense yourself falling forward, lightly press the floor away with
your fingers, concentrically contracting your triceps to return to the balance point.
Eventually, as you get even stronger, you can work toward straightening your
elbows by further concentrically engaging your triceps.HOW TO
Use eccentric contractions in
Parsva Bakasana (Side Crane Pose)
PHOTO: RICK CUMMINGS; MODEL: LINDSAY GONZALEZ; HAIR/MAKEUP: BETH WALKER; TOP: VIMMIA; BRA: CHAMPION; BOTTOMS: PRANAOUR PROS An NYC–based yoga teacher
and Feldenkrais practitioner, Joe Miller
teaches anatomy and physiology trainings
for yoga teachers and students around the
world. Learn more at joemilleryoga.com.
Model Lindsay Gonzalez (breatheonboard
.com) is a teacher at Kindness Yoga in Denver,
where she helps run their 200-hour yoga
teacher trainings. She also offers SUP yoga
trainings and international retreats.