Actress Chyler Leigh in a half lotus pose, meant for yoga beginners. A popular and well-known yoga pose it brings up the question: yoga looks easy but I need something that challenges my body? When people get around to doing yoga, it dawns on them: my body is sore all over, why's yoga sooo hard?? Yoga is an all round exercise system that builds strength, flexibility, balance, and yes it burns calories and makes you slim. As you get more into yoga, you discover that it also provides mental health benefits, and helps the body to fight diseases.