Lack of sleep is not the only thing sapping your energy. Little things you do or don't do can exhaust you both mentally and physically. Some of the reasons that make you tired are in my opinion are here.
Many of us skip daily workout to save energy. But the fact is it works against us. Researchers found instead of skipping entirely when tired, going for simple walking without being brisk can make you active. Not consuming enough Iron, trying to be a perfectionist, making mountains out of molehills,skipping breakfast are some of the other reasons that make you tired.