Yes! You can do yoga in bed both in the morning and at night. Try this stretching routine when you first wake up: bend your knees and hug them in towards your chest. That will release your lower back, which tends to be very stiff after you've been sedentary after 8 hours. With your knees still bent, let your knees fall over to the right and keep your thighs parallel at hip level. Hold your left arm out straight out to the left, and use your right hand to press your left thigh down for a deeper stretch. Relax your left shoulder blade down your back. Then, switch sides. Stretch your left leg out long (left calf on the bed) and lift your right leg up to the ceiling. Lace your fingers around your right hamstring or calf (whatever is available to you), and tug your leg closer towards you. Try to straighten your leg as much as possible. Hold for at least a few breaths. Then, repeat that on the other side. Bend your left knee and press your left foot onto the bed, then hook your right ankle over your left thigh. Then, place both hands behind your left hamstring (right hand through the "keyhole"). Tug your left thigh closer towards you while simultaneously using your right elbow or hand to press your right thigh away. Then, switch sides. That will help stretch your glutes and can help relieve sciatic pain.