As in life so in practice, or, as life gets complicated so can practice. Yoga develops complexities as you evolve in the practice, just as life can. More time commitments, sacrifice and greater demands. "What to leave in and what to leave out" is a parallel theme.
There are many forms of yoga. Yoga is history and culture that pervades the beginnings of modern exercise and movement. Yoga is simple yet philosophical enveloping medical science with the metaphysical world.
Pattabh Jois states, "Yoga practiced without Pranayama (breathing exercise), Asanas (physical postures), Bandha locks or (body locks), and Meditation is merely physical exercise." Exercise is good and Yoga is good, they both have different outcomes. Pranayama is Breathing with control. Techniques that cleanse the body physically and energetically. Asana are the physical aspect of yoga, the postures. Bandhas are the locks that control energy flow. Directly affecting the nervous system and elevating energy towards higher consciousness. Meditation is observation. To observe thought without judgement, then to concentrate on a singular point, and finally become one with source. If the outcome desired relies on Yoga, the practice is important.
So as yoga evolves into contemporary forms, the importance of what makes yoga more than just exercise must be remembered. Endeavor to become more than a pose or technique. By combining the components of traditional yoga the practice becomes whole and is simple.