Since my first memory, I tired easily. Seems it takes a long time to build up endurance. I do strength training approx 3 times a week. Yet at certain time, I still will feel fatigued. I get more than enough sleep. I have always needed more than my friends. I eat somewhat healthy. I am bipolar since I can remember, more Depressed than manic. I take my recommed dailey dose of vitamins. Womens centrum, caltrate, fish oil.