Ok, a couple of questions. What area assuming you're in the US are you in? It makes a difference in what I would suggest. As an example, we went to a trampoline park today. We fundraised for the cost. The school does not give us money. There is always a way to raise money but that is another subject.
We give out awards every Friday. They are not trophies. The awards are rocks with the name of the team and the name of the award winner on them. You just have to buy a magic marker.
We are in a cold place. We are already making plans to go sledding. The kids bring their own sleds. Sled down the hill, run up. Great workout? Probably not ideal but they are having fun getting exercise. The other kids in the school hear that we are going to trampoline parks, sledding, awards, etc. and they join. More kids and families to raise funds.
In the summer our XC team finds different areas to run from, have a day we do artwork with stuff we found on the run, have a run where they get a popsicle in then middle of it. I bring a radio with music to practice and they do core work and their warm ups to it. You don't have to do much to get them excited.
In the middle of all of these fun activities they are training hard on the other days.
I'm not saying you do this but make sure you are complimenting the kids that choose to be there and not complaining about people who are not there.