Hard physical work can leave you exhausted. That’s because physical activity causes a buildup of a toxic muscular sludge known as lactic acid, that contributes to muscle fatigue. Surprisingly, thinking hard can affect your brain the same way…

Fat, foggy and forgetful. It’s safe to say that a lot of us feel this way, especially when we hit middle age. And, while many people, even doctors, write it off as just a part of aging, that’s not the case…