Is working out worth it?

I made the attempt last week to go to the gym to try to start working out again. I have a health club membership through work so I can go whenever and not have to pay for it. So when I don't go at least I am not wasting the money. It doesn't cost work much either because they have me on as a nanny add on so it's only $20/month. But it is nice to be able to go when I want. The only thing is that I have to make an infant reservation for Emily so I have to plan it and know when I am going to be there for the hour and half I am allowed. The first day I made it and the kids were great. Stephanie didn't want to leave. Then the next day we went back and were a half hour late so I only had an hour to work out (and shower). Emily didn't do so well this time so she was happy to see me but mad because I left. Then that night I could tell she was coming down with a cold. So she is all stuffed up and having trouble eating and sleeping. Great, both of which she doesn't do well at when she feels fine. I know the kids need to get exposed to germs and she could've gotten sick from being at the gymnasium the day before but every time I go work out they get sick. We haven't been there since October because that's what happened. I know it will happen when Stephanie goes to school but I would like to prevent it now if I could. To top it off, Emily gave me the cold now too. Oh well, summer is still a long way away so no shorts here anytime soon.