Using of the running in possibilities have shown to be a very good attack weapon.
Running in means that a team changes from a 3-3 attack to a 4-2 as a player (without a ball) changes position by running against the goal circle or to the opposite side. It often brings the defending team out of 'balance' and in that period there will normally be several excellent passing and scoring possibilities. If the running in doesn't bring a scoring, the running in player seeks her own place again in the 3-3 attack system.
The running in player is often the playmaker, but wings and backs are quite as useful. It gives further playing possibilities and causes that it is more difficult for the opponents to make a tactical counter measure.
Running in can be performed against all defending systems (6-0, 5-1, 3-2-1) and the running in player may vary her running in (change of position):
1. Running in following the movement- and passing rhythm (which is the most common)
2. Running in after a short break (after passing) which breaks the rhythm. It gives a bigger moment of surprise.
3. Running in when the ball is on the opposite side. Can be used by wings and backs, and it almost always surprise the defense.

All the exercises can be practiced on both sides.