Playing a variety of tag games during PE class gives the third-graders great physical fitness while enjoying the class with their friends. Have the kids play a traditional game of "everyone's it" where kids run around the gym trying to tag others, with the last man standing being the winner. Each time a kid is tagged, he is "out" and must sit on the sidelines until all of the other kids have been tagged out. Introduce a different version of tag such as "capture the flag" that uses the same principles except that the kids are split into two teams with a team flag behind each group of kids on opposite ends of the play area. The object is to grab the flag from the other side without being tagged out.
Play games that involve teams or individuals competing against each other for some healthy competition and physical fitness. For instance, tug-of-war may be played with two separate teams, each team pulling on a side of the rope. (Be sure students have sturdy gloves to protect their hands.) Beanbag toe tag is also a fun fitness game for students where a net is separating two teams in the middle of the gym or play area and the object is to slide a beanbag under the net to hit the feet of an opposing team member, who will then be "out."
Combine balance, strength and fitness by playing a game that involves all three such as the hula-hoop challenge. Separate the class into small groups and place a large hula hoop for each group on the ground in front of them. At your call, each group must try to fit themselves inside the hula hoop without falling or stepping outside of it. Make it to where the number of students can fit in the space of the hula hoop, but very snugly. Set a timer for 15-20 seconds before allowing them to exit the circle.
Combine fitness with critical thinking in a fun PE game for third-graders called "the infinite circle." You will need a rope for each student in the class. Break them up into pairs. Each student will tie one end of his rope onto one wrist, with one team member tying the other end of his rope onto his other wrist. The second team member reaches her arm through the circle loop of his team member's rope and then ties her rope onto her free wrist. Each team must untangle themselves without untying the rope by twisting, turning and using flexibility and strength.