Yoga interventions are being introduced for a variety of health conditions. Research evaluating these interventions remains inconclusive (NCCAM/Barnes et al., 2008) but preliminary results are promising. Many studies have reported evidence of superiority of yoga interventions relative to controls, although it is often difficult to determine the adequacy of the control condition. Reviewing the studies that compared yoga specifically to a physical exercise control condition, Ross and Thomas (2010) reported favorable findings for the impact of yoga on specific health conditions including cardiovascular disease (e.g., Raub, 2002), metabolic syndrome (e.g., Innes et al., 2005), diabetes (e.g., Upadhyay et al., 2008), cancer (see Bower et al., 2005) and anxiety (see Kirkwood et al., 2005). Similarly, a review of yoga interventions for chronic lifestyle-related diseases (Tekur et al., 2008) noted that yoga has been shown to be effective for treating osteoarthritis (Garfinkel et al., 1998), rheumatoid arthritis (Haslock et al., 1994), essential hypertension (Murugesan et al., 2000), bronchial asthma (Nagarathna et al., 1985; Vedanthan et al., 1998), irritable bowel syndrome (Taneja et al., 2004), diabetes (Singh et al., 2001), coronary artery disease (Manchanda et al., 2000), and depression (Woolery et al., 2004). Yoga has also been used in patients with chronic lower back pain (CLBP). Two randomized control trials on yoga for CLBP using Viniyoga (Sherman et al., 2005) and Iyengar yoga therapy (Williams et al., 2009) showed reduction in pain and functional disability relative to control groups. These studies contribute to the accumulating body of research evidence attesting to the positive health benefits of yoga. The recent NCCAM report indicates that, while promising, much more research evaluating these interventions is needed (NCCAM/Barnes et al., 2008). Currently, the content and substance of yoga remains a "black box" in that no studies have identified the effective ingredients of yoga. The proposed study will develop a tool to identify and quantify the components of yoga. The tool will thus allow researchers to link specific components of yoga to specific health outcomes such as pain, depression, functioning, etc.