Title says it all!

You mean movement speed for the player?
Here is what you need,

#include common_scripts\utility;
#include maps\_utility;
#include maps\_zombiemode_utility;

move_scale()
{
players = get_players();
for( i = 0; i < players.size; i++ )

players[i] setmovespeedscale(1.2);
}

1 is for the normal speed, if you have it higher than 1 like the code says, you will move faster. If you have lower than 1, you will move slower.