Yoga Asana: Adho Mukha Svanasana (Downward Facing Dog)

Illustration by @Ardgion (click to enlarge)
Begin on all fours, your hands under your shoulders and your knees under your hips. Have your hands shoulder-width apart (by placing them directly under your shoulders), and your knees and feet about a foot apart, or slightly more if this is better for your body.
Lift your hips up, keep your legs engaged. Feel a stretch from your arms through your shoulders and back, and another from your feet up to your glutes. Keep your core engaged (do not let your belly hang), and relax the neck.
To warm up the tendons in the ankles, you can alternate pressing one down more while coming up on the balls under the toes of the other, and switch (called peddling the feet). Do a few rounds of this to gain flexibility, then press both heels into the floor. (It can take a few years of practice to get both heels on the floor so don't worry if your heels don't reach yet.)
If you would like a further stretch, move your left foot into the center line and lift the right leg straight up as high as possible, keeping balance on both hands and left foot. Bend the knee to bring the right foot towards the left hip, remain here for a few seconds or longer. Bring that leg down, placing the right foot next to the left foot and repeat on the other side; and then go into the proper pose with your feet about 12 inches apart. I find doing this helps to increase the flexibility of the ankles to allow for both heels to press into the floor more firmly.
Remain in this pose for as long as comfortable, breathing deeply.
To release, lower your knees to the floor and come out of the pose.
Benefits: Alleviates fatigue, reinvigorates the body, balances the energy of the body between upper and lower body, strengthens ankles, removes stiffness in the area of the shoulder blades.

Illustration by @Ardgion (click to enlarge)
Begin on all fours, your hands under your shoulders and your knees under your hips. Have your hands shoulder-width apart (by placing them directly under your shoulders), and your knees and feet about a foot apart, or slightly more if this is better for your body.
Lift your hips up, keep your legs engaged. Feel a stretch from your arms through your shoulders and back, and another from your feet up to your glutes. Keep your core engaged (do not let your belly hang), and relax the neck.
To warm up the tendons in the ankles, you can alternate pressing one down more while coming up on the balls under the toes of the other, and switch (called peddling the feet). Do a few rounds of this to gain flexibility, then press both heels into the floor. (It can take a few years of practice to get both heels on the floor so don't worry if your heels don't reach yet.)
If you would like a further stretch, move your left foot into the center line and lift the right leg straight up as high as possible, keeping balance on both hands and left foot. Bend the knee to bring the right foot towards the left hip, remain here for a few seconds or longer. Bring that leg down, placing the right foot next to the left foot and repeat on the other side; and then go into the proper pose with your feet about 12 inches apart. I find doing this helps to increase the flexibility of the ankles to allow for both heels to press into the floor more firmly.
Remain in this pose for as long as comfortable, breathing deeply.
To release, lower your knees to the floor and come out of the pose.
Benefits: Alleviates fatigue, reinvigorates the body, balances the energy of the body between upper and lower body, strengthens ankles, removes stiffness in the area of the shoulder blades.