1. Open OPTIONS
2. Click CONTROLS
3. Click the INTERACTION tab
4. Scroll all the way down until you see "HOLD LOW-READY"
5. Keybind it to whatever key you feel like using to "run" (I personally use the SHIFT key)
6. If you used the SHIFT key, click on the MOVEMENT tab and clear the WALK key
7. If you used the SHIFT key, click on the TEAMWORK tab and clear the HOLD COMMAND key
8. Apply settings

You should now be able to go into a game and "run" faster, making your speedruns faster :)

Video guide: