For today’s edition of Dear Mark , I’m answer two questions from readers. First, does Bikram yoga qualify as sprinting or high intensity training? It’s certainly intense, and it’ll make you sweat bullets and work hard to the point of nausea, but does it actually accomplish the same training effects as sprinting or intervals? Find out down below. Next, you often hear that body fat is the main repository for environmental toxins. This is true, but does that mean the body “holds on” to body fat to prevent systemic dispersal of the toxins it contains? Can stored toxins make losing body fat harder that it already is? Let’s go: I love doing Bikram yoga and wonder if you would consider it a sprint day or a high intensity day, or both? Thanks, Rebecca Neither, actually. What do sprinting and other types of high-intensity training do to the body ? They preferentially burn body fat. Bikram yoga has been shown to induce modest reductions in the body weight of obese subjects, but that’s