Caution: Supta Virasana, the reclining variation of Virasana, is an intermediate pose. DO NOT perform this pose unless you can sit your buttocks relatively easily on the floor between your feet.
Step-by-Step Instructions

1. (soup-tah veer-AHS-anna) supta = lying down, recliningvira = man, hero, chief (compare Latin vir, “man,” the root of English words virile and virtue)
2. Perform Virasana. Exhale and lower your back torso toward the floor. First lean onto your hands, then your forearms and elbows. Once you are on your elbows, place your hands on the back of the pelvis and release your lower back and upper buttocks by spreading the flesh down toward the tailbone. Then finish reclining, either onto the floor or a support blanket or bolster.
3. If your front ribs jut up sharply toward the ceiling, it’s a sign of tight groins, which pulls your front pelvis toward your knees and causes your belly and lower back to tense. Use your hands to press your front ribs down slightly and lift your pubis toward your navel. This should lengthen your lower back and lower it toward the floor. If it does no’t, raise yourself onto a higher support. Then lay your arms and hands on the floor, angled about 45 degrees from the sides of your torso, palms up.
4. Sink the heads of the thighbones deep into the back of the hip sockets. It’s alright to lift your knees a little away from the floor to help soften your groins; in fact, you can raise your knees a few inches on a thickly folded blanket. You can also allow a little bit of space between your knees as long as your thighs remain parallel to each other. Do not, however, allow the knees to splay apart wider than your hips – this will cause strain on the hips and lower back.
5. To begin, stay in this pose for 30 seconds to 1 minute. Gradually extend your stay to 5 minutes. To come out, press your forearms against the floor and come onto your hands. Then use your hands to lift your torso into Virasana. As you come up, lead with your sternum, not your head or chin. Come out of Virasana in the recommended manner.

POSE INFORMATION
Sanskrit Name
Supta Virasana
Contraindications and Cautions
If you have any serious back, knee, or ankle problems, avoid this pose unless you have the assistance of an experienced instructor.
Modifications and Props
If you’re not able to recline fully on the floor, set a bolster or one or more folded blankets behind yourself to fully support your spine and head. Use as much height as you need to make the position reasonably comfortable.To help release the groins, lay some weight across the creases of the top thighs where they join the front pelvis. Start with a 10-pound sandbag and gradually over time increase the weight to 30 pounds or so.
Deepen the Pose
You can also involve the arms in this pose. Inhale and raise your arms toward the ceiling, parallel to each other and perpendicular to the floor. Rock back and forth a few times, further broadening the shoulder blades across your back, then stretch your arms overhead, on the floor, palms up toward the ceiling. Rotate your arms outward, so the outer armpits roll toward the ceiling, and pull your shoulder blades down the back toward your tailbone.
Theraputic Applications

• Arthritis
• Asthma
• Diarrhea
• Digestive problems
• Flat feet
• Head cold
• Headache
• High blood pressure
• Infertility
• Insomnia
• Intestinal gas and acidity
• Menstrual discomfort
• Respiratory ailments
• Sciatica
• Varicose veins

Preparatory Poses

• Baddha Konasana
• Balasana
• Bhujangasana
• Gomukhasana (leg position)
• Virasana

Follow-up Poses
Like its upright cousin, Supta Virasana is an excellent preparatory pose for many asanas, including Padmasana, Baddha Konasana, Bakasana, most standing poses, and any inversion and backbend.
Beginner's Tip
If your thighs insist on sliding apart in this pose, you might try one of two short-term solutions: bind your thighs together with a strap positioned around the mid-thighs; or squeeze a 2- to 3-inch thick book between your thighs. In either case be sure to draw your inner groins sharply up into your pelvis.
Benefits

• Stretches the abdomen, thighs and deep hip flexors (psoas), knees, and ankles
• Strengthens the arches
• Relieves tired legs
• Improves digestion
• Helps relieves the symptoms of menstrual pain

Partnering
A partner can help you get a feel for the proper movement of the top thighs in this pose. Have her stand at your knees, bend forward, and place her hands on your top thighs, which can be padded with a folded sticky mat. She should then press lightly down on your thighs and turn them inward, rolling the inner thighs toward the floor. Tell your partner if you want more or less pressure on your thighs.
Variations
Before doing Supta Virasana you can start with its halfway variation, Supta Ardha Virasana (are-dah = half). To sit in Ardha Virasana, draw just your right leg back into Virasana. You can keep your left knee bent with the foot on the floor, or straighten your left leg by pushing out through the heel. Then recline as described above, either onto a support or the floor, following all the cautions. Come out as recommended for Virasana, then repeat with the left leg back.

Source: yogajournal.com