Why/how is the WR run sped up? is that an in game thing?

Is there a specific thread or ...?
ps i might just be blind but cant see one XD

legend , cheers m8

thanks for that guys , new question XD the scuba guy ive seen in some runs people skip the swordsmen and leave the screen and when they return he is out of the water , i tried to copy this exactly but cant get him up without killing the guys, what am i missing?

Hi Im trying to get into speedrunning minit but I just cant seem to get the snake cave right without the light, is there a certain method used to get trough it or is it simply just learn the layout? any help would be appreciated thanks