The key to increasing flexibility through yoga postures or strectching exercises is the amount of time you spend in each stretch. It takes roughly 30 seconds for the muscles to begin to release into a stretch. So, you need to hold those stretches for a minimum of 45 seconds, to start, building the holding time slowly. It’s okay to have a little discomfort, but you NEVER want to feel pain. Postural alignment is very important, because if you are in an incorrect position, you can create an imbalance in your body. A yoga teacher with good knowledge of alignment is a great help!