Cool down after training. Jog at an easy, continuous pace to lower the heart rate, keep the breathing relaxed, then hold static stretches for the main muscle groups.
Players jog a slow, continuous lap of the grid, gradually lowering the pace and letting the breathing settle. After a couple of minutes of easy jogging, move into static stretches, holding each for 20 to 30 seconds for the calves, hamstrings, quads, hips, and groin. Keep it calm and unhurried.
Evidence that a cool-down prevents muscle soreness or meaningfully speeds recovery is considerably weaker than most coaches assume. The research on post-exercise stretching in particular has not supported the claims made for it over several decades. That is worth knowing before you tell a squad that ten minutes of jogging will stop their legs aching on Tuesday, because it probably will not.
There are still sound reasons to run one, and they are worth stating honestly rather than dressing up. An easy jog brings the heart rate down gradually instead of stopping dead, which is more comfortable and avoids the light-headedness that can follow ending a hard session abruptly. Gentle movement loosens off muscles that have been working, and players report feeling better for it, which counts for something even where the physiology is unclear.
The strongest argument is the one that never appears in a coaching manual. A cool-down is the only part of a session where the entire squad is together, moving slowly, and able to talk. It is when a coach finds out how a player's week has gone, and when training gets a proper ending instead of trailing off into the car park.
So run it, but run it for what it does. Easy continuous pace with no stops and starts, let the breathing settle, then hold static stretches lightly without bouncing. Keep it short.
If you are pressed for time, cut it rather than rushing it. Four minutes done properly beats ten minutes of standing about.
Save it to your private drills, then change the animation, adjust positions, swap equipment, or drop it into a session block. Or start from a blank pitch and build your own.