If you look at one pound of fat and one pound of muscle side by side, you will see how much smaller the muscle is, although it has the same weight. This means that the more muscle you have on your body, the less space you take up. Many people - both men and women-think that lifting weights makes them look like a Bodybuilder. That is, if you study physics, you turn into Einstein. The amount of time, food and discipline required to become enormous with weights is almost a full - time occupation-and is sometimes influenced by illegal substances. So include strength training. You feel slimmer and look slimmer and speed up your metabolism.