The very definition of exercise implies that it is good for our health and fitness i.e that it should pose little risk and aim to improve both of the aforementioned categories. Unfortunately, exercise enthusiasts and practitioners alike have falsely grouped many types of physical activity under the general category of exercise and as a result have led consumers to believe that they all offer equal benefit to our health and longevity. When in reality this couldn't be further from the truth. Additionally, some types of physical activity (falsely deemed exercise) pose an inherently high risk for very little reward. There indeed exists a hierarchy of physical activity as it pertains to benefits and risks that spans from little risk and high benefits to high risk and little benefit.
The point here is not to say that we should avoid all types of sport or that yoga does not offer us some form of benefit. However it should challenge us to reconsider what we deem “exercise” as well as the risks associated with the various types of physical activity that we may or may not choose to partake in. All too often, we impulsively choose from the top of this list and then wonder why we receive the results (or lack thereof) that we do.