A run can be started when you are 6 or more steps away from your opponent by tapping f,f. Your possible options during a run depends on the amount of steps you have taken, the character your are playing with and the position of the opponent. This first chart will break down the options depending on the amount of steps.
 
Steps Taken Option Description
6 The run starts at the 6th step
from 6 to 22 Running Stomp on a grounded opponent
from 11 to 18 Running Tackle on a standing, ducking or back turned opponent
from 12 to 22 You can do a Head Dive, Slide or Slash Kick
from 18 to 22 Shoulder Ram on a standing, ducking or back turned opponent
22 The run ends at the 22nd step
 
 
 

The following chart contains the command and range analysis for the default running attacks. Refer to the chart above as to when you can execute these particular attacks.
 
Action Command Range Note
Stop Running b_d/f -  
Side Step Run Cancel u_d -  
Crouch Run Cancel D -  
Running Stomp N_F -  
Running Tackle N_F T #1
Shoulder Ram N_F !  
Head Dive 1+2 m GB
Slash Kick 3 m #2 GB
Leaping Heel Kick 3 m #3 KND
Slide 4 L #4
Foot Notes #1 Craig Marduk can use his usual Tudo Mount attacks after a Running Tackle.
#2 All male characters and Panda execute this attack unless otherwise noted below.
#3 All female characters execute this attack unless otherwise noted below.
#4 Unlike every other character, Jack-5 and Kuma to not cross up the opponent after a Slide hits.
 

Not all characters can do the default running attacks. Below is a list with exceptions, if an attack is not listed it equals the default attack. Special running attacks are also listed on the individual character move lists. Frame rates and damages for these moves are the same as if the moves were done from standing.
 
Character Running Command Resulting Move Name
Christie Monteiro 3 f,f+3 Lunging Brush Fire
Craig Marduk 3 f,f,f+3 Bicycle Kick
Feng Wei 3 f,f,f+3 Severing Sword
Jack-5 3 3 Face Buster
King 3 f+3 Front Kick
4 d+3+4 Ali Kick
Lee Chaolan 3 f,N+3 Shredder
Nina Williams 3 f,f,f+3 Leaping Heel Hold
Paul Phoenix 3 f,f+3 Shredder
Roger Jr. 3 f+3 Promenade
4 d+3+4 Ali Kick
Steve Fox 3 3 Left Weave
4 4 Right Weave
Yoshimitsu 3 3 Pirouette Kick
4 f,f+4 Fubuki