If you wake up feeling like you didn’t sleep at all, you drag through your day, you have trouble concentrating or doing anything productive, you know how lack of energy can affect your life. There are variety of reasons for not having adequate energy: maybe you’re just too busy to get a square eight hours of sleep. Maybe you suffer from a sleep disorder. Maybe you have an iron deficiency or your diet lacks enough protein. Maybe you have low testosterone. Whatever the source of your fatigue, you’re probably most concerned with how lack of energy can affect your life. …