Start standing with your feet wider than your hips and turned out slightly. Pull your core in toward your spine and make sure your hips are facing directly forward.
Looking straight ahead, bend about halfway down at the hips and right knee, ensuring that your right knee remains behind your toes. As you bend, extend your left arm out in front of you. Remember to keep your core pulled in, pelvis facing front, and shoulders aligned over your hips.
Hold for a few seconds, then shift your weight to the left and repeat on your other side, bending your left knee and bringing your right arm out in front of you.
Continue shifting back and forth between legs for 30 seconds.
If you feel tension in your shoulders, keep your arms lower. If you're dealing with knee pain, don't bend quite as deeply into the lunge.