There are unlimited benefits to Bikram Yoga. It reduces stress, improves sleep. Develops muscle tone and builds strength and stamina. Helps weight reduction, improves circulation and boosts your metabolism. Strengthens your immune system. Improves breathing. Excellent for back pain, sports injuries and bad posture. You may also develop a better memory and concentration.

but I am not flexible...

This is one of the most common misconceptions that prevent people from doing Yoga. Yoga is not about how flexible you are. It is about stretching your body and spine in all directions. All that matters is that you try the right way, working to your own personal edge to obtain all of the benefits.