There are no right and wrong answers, but one thing that you can do when deciding on a fitness team name is to make it both motivational and funny, a la "Will Run For Beer" or "The Slimsons." You can make use of the play on words and generate a chuckle by naming your squad "Lighten Up" or "No Weigh."
Naming a team is one of the most enjoyable things to do when you are in a fitness group. The most important factor is for every one of the members to buy into your mantra and live by it. It also helps the group to put on an identity that separates them from all the other fitness groups.
Joining a fitness group is not for everybody, but it is highly recommended by fitness experts if you are up to it. Farrell's Extreme Bodyshaping points out the group exercising benefits: namely motivation, competition, community, accountability, structure and, of course, fun. When you're in a group, you have someone to lean on, encourage you to carry through when struggling and challenge you to push over physical limits, all while sharing a hearty laugh at the same time. That way, exercising brings loads of enjoyment, and everything feels lighter than what is purported to be. That includes your weight, too.