7. Working out exhausts your body and makes you tired.
Training, especially when using free weights, will actually give you more energy. When you first start, your body is used to being sedentary, so it may temporarily resist moving more. In as little as two weeks, though, you may actually crave working out as your energy sharply increases and you start to look and feel amazing. People who work out often are far more productive. They have a lot more sustainable energy through the day because they are physically fit.