One of the things we've seen in the last 20 years increasingly addiction being referred to as a brain disease or a brain condition. The reason why we've done that is, in the last 20 years, we can actually see addiction in the brain. So if I could show you SFMRI pictures, I could show you your brain getting high. What happens is, your brain getting hot, there's a lot of physical activity, there are a lot of electrons firing in the brain. You can, literally, see someone get high and you can see them crash when the brain goes cold. In a matter of thirty minutes, you can see the brain rise, get real hot; and you can see it crash, below normal, and become cold. That below normal cold is as unpleasant as the high is pleasant. People use drugs to get back to normal because of that pain. If I look over days, what I see is that people have used substances, their brain no longer reaches normal functioning. They are not having that pleasure. Ten days after use, their brain is still cold. There aren't normal levels of activity. In treatment, this is called anhedonia, which is the inability to experience pleasure. About a month into sobriety, you've stopped using, but you don't enjoy the sun, you don't enjoy your child, your friends, or playing games; you're just not getting any pleasure. That's because the brain has, kind of, a chemical traumatic brain injury. Just like if you had a stroke or an accident, when you've used drugs, you've altered your brain in ways that we can physically see. It takes time for your brain to heal. Even a hundred days after you've stopped using, your brain is only back up to about 60 percent of normal. That's why when we talk about treatment needing to last at least 90 days and longer, it's very important to get you to engage in activities that help your brain heal and restore some semblance of a normal life. One of those activities that's really a new thing in terms of addiction, is exercise. Exercise has an effect on all kinds of health conditions and, in particular, it affects the brain. When you exercise, you increase something called the neuroplasticity of the brain which is the rate at which the brain heals. It doesn't matter if it's a stroke, if it's a physical brain injury of if it's a chemical injury from using drugs and alcohol. Exercise is helping your brain become active again and heal, and it's helping the recovery process and get you more stable faster and for longer.