Learn half moon (Ardha Chandrasana) properly: hand on a block, open the pelvis, lift the back leg. What studies show about glute and ankle muscle work.
How high do you have to lift the leg in half moon for it to work? The honest answer: the leg should go to hip height, not higher, and the hand belongs on a block, not on the floor. Ardha Chandrasana ("half moon") is a sideways-opened one-legged balance: one foot stands, one hand supports, the other leg stretches out horizontally behind you. It looks elegant and, honestly, is one of the more demanding standing poses for the glutes.
Measurements show this. In a lab study of 31 healthy adults (18 to 35 years), the gluteus maximus reached 63.3% of its maximal voluntary contraction in the lifted leg (almost two thirds of what it can produce in a maximal effort) and 61.7% in the standing leg in half moon, the gluteus medius 41.9% in the lifted leg. Half moon led among the five poses tested [1]. And a second study showed that in one-legged poses the shin and calf muscles work harder than the thigh muscles [3]. For you that means: your standing foot does a lot.
Why the block? Because it brings the floor to you. Without a block you tip the torso forward, turn the chest down and lose the opening this posture is about. With a block the chest stays open, and the lifted leg can work at hip height. This is practice experience that holds up with almost every beginner.
Go into triangle: legs wide, the front toes point forward, the front hand rests on the shin. Place the block about a hand's width in front of the front foot on the little-toe side. Choose the block height so you do not have to contort yourself.
Bend the front knee slightly and push the weight forward. The front hand lands on the block, the back leg becomes light. The standing leg stays straight but not locked.
Milestone: You stand 5 breaths steady in triangle with a hand on the block.
Lift the back leg to hip height, the foot actively flexed, toes pointing sideways. Press the back heel away so the leg works. The pelvis opens upward.
Turn the chest open. Gaze first down at the block, then to the side, then (if your neck allows) to the ceiling. Breathe five to eight calm breaths. To release, set the leg down and move into triangle.
Milestone to move on: You hold half moon for 5 breaths per side without wobbling, hand on block and gaze down. Then you can let your gaze wander.
One-legged poses mean fall risk. For reassurance: in a review of nine observational studies, the fall risk of yoga practitioners was comparable to that of non-practitioners (odds ratio 0.90), and serious events occurred in 1.9% [4]. That does not mean half moon is harmless, only that you need not shy away from practicing it with a wall and block. The back of the standing leg is a problem area in yoga [5]. If you sink too deep into the standing leg, you load knee and glutes. Imagine a wall behind your back and never practice without a firm stance. This guide explains and motivates; it does not replace supervised training.
Rest the back leg against the wall. Stand with your back to the wall, go into half moon and let the back heel rest against the wall. This is a practice trick: you feel whether hip and leg lie on one line, and you can concentrate on balance without falling. After a few weeks, take the foot off the wall.
Mainly the glutes: the gluteus maximus reached 63.3% of maximal contraction in the lifted leg, the gluteus medius 41.9% [1]. In addition, shin and calf muscles work at the standing foot [3].
With the hand on a block, the gaze on a fixed point on the floor and the standing leg slightly bent. Lift the back leg only when you are stable in triangle with the block. A wall behind your back makes it easier.
Start with five breaths per side. In lab studies, half moon was held for 15 to 30 seconds [2][3]. Time frames such as "secure in 4 weeks" are not proven and depend on your strength.
Start with your gaze on the block or the floor. Only when you are stable do you look to the side, and last to the ceiling. The neck stays long, you do not turn it by force. If you wobble, go back to looking down.
It is intermediate level. If you can do triangle and tree securely, it is a good next step with a block and wall. Otherwise stay with triangle.
Eagle Pose (Garudasana): One-Legged Balance With Wrapped Arms and Legs