I hear a lot of people say (about a lot of things, not just fitness) that they don't have the willpower to live the life they want. To all of those people (myself included): you just have to choose to do it. It's not easy, but it is simple.
The physical practice of yoga is often times strenuous as it tones the body and increases weight loss. Although many practice yoga because it relieves stress and clears the mind, the added benefit of maintaining a yoga practice is a healthy body. If weight loss is going to improve an individual’s quality of life, then incorporating challenging yoga postures is beneficial for that particular goal.