The higher your agility is, the faster that you will be able to run. The less weight on your body the faster you will be able to run. The reason why is fairly obvious when you think of how it would work in real life. Once the weapon is gone you should immediately run faster. Holding down the button you use to reload is usually the way to holster your weapon. If you put your weapon away you will free up your arms to be able to focus on running. Here is what you can do to make your character run faster in Fallout 3. Pushing forward on whatever controller you use will make your character walk forward. There is no button that will make your character sprint, but there are a few simple ways to increase the speed at which your character runs.