Yoga is probably one of the most common activities companies encourage their employees to do. It makes sense, given the numerous health benefits scientists have found the practice to have. But not all yoga poses are completed equal, and because free time is limited at the office, you want to pick ones you know will deliver. These are the ultimate moves to perfect and complete throughout your entire workday.

When you need to stay focused and grounded: tree pose (Vrksasana)

Why it's effective: When you do tree pose, your brain has to work together with your nervous system to figure out where you are in space, calculate the amount of correction necessary to keep you balanced and then turn that analysis into physical adjustments. As the brain collects information about pressure, stretch, tilt and other factors, it also receives information from your eyes. As the brain puts all this data together, it compares the visual data with an internal image you have or mentally create about where your body should be, trying to get the two pictures to match up. Because you have to concentrate visually to stay upright, the pose gets your brain used to honing in and saying no to all the shiny distractions that could impede your work.

Find your alternative: Leg extension with toe bind (Utthita Hasta Padangustasana), eagle (Garudasana), Lord of the Dance (Natarajasana), warrior III (Virabhadrasana III)

When you are stressed and need to chill out: corpse pose (Savasana)

Why it's effective: Through a combination of deep, rhythmic breathing and deep pressure stimulation from the floor, corpse pose reduces the "fight or flight" response of the sympathetic nervous system. As the activity of the sympathetic nervous system decreases, the parasympathetic nervous system kicks in, keeping cortisol levels, heart rate, muscle tension, digestive function, secretion and other processes back toward homeostasis.

Find your alternative: Reclining bound angle pose (Supta Baddha Konasana), side-lying corpse pose (side-lying Savasana), crocodile pose (Makrasana), revolved abdomen pose (Jathara Parivartanasana)

When you're tired: bridge pose (Setu Bandha Sarvangasana)

Why it's effective: As you push your buttocks and upper legs off the floor, your chest and shoulders naturally fall into a more open position. Subsequently, you give the lungs more room and allow them to expand fully. At the same time, gravity pulls blood backward toward the head. You thus get more oxygen and nutrients to the brain, which gives you a natural pick-me-up.

Find your alternative: camel (Ustrasana), wheel (Urdhva Dhanurasana), cobra (Bhujangasana), fish (Matsyasana)

When you've been sitting too long: warrior pose (Virabhadrasana)

Why it's effective: Repeated, prolonged sitting at work typically causes the hip flexors and muscles of the lower back to tighten, allowing the hamstrings, gluteals and abdominals to stretch and atrophy. This imbalance can cause anterior pelvic tilt, which is associated with lumbar pain and other problems. But when you move into the warrior position (essentially a modified lunge), you stretch the hip flexors while strengthening your hamstrings and glutes, correcting the imbalance. The abdominal muscles have to fire to assist with keeping balance in the pose, as well. At the same time, lifting the arms up allows full expansion of the chest. You can breathe more deeply and get more oxygen, so you feel more energized.

Find your alternative: Extended side angle pose (Utthita Parsvakonasana), crescent (Anjaneyasana), monkey (Hanumanasana), one-legged king pigeon (Eka Pada Rajakapotasana), bridge pose (Setu Bandha Sarvangasana)

As with any form of exercise, it's smart to check with your doctor before you start your yoga practice. Additionally, based on your strength, balance and other medical factors, you might find that yoga tools like a block, strap, towel or roll make poses more comfortable and manageable. Yoga mats are always handy if you're going to be working on a hard floor. Once you've got your equipment set, work within your own range of motion, respect what your body gives you each day and have some fun!