Most apps don't run in the background very long. Some more than others. But it's not a battery issue. The 3 big battery users are screen brightness, push notifications, and location services. So turn your screen brightness down as much as possible, turn off unnecessary app push notifications, turn off location services you don't need.
Aside from my iCloud e-mail, what else "pushes?" And that actually doesn't make sense to me. Now "fetching" I can see as a battery drain, especially if you have it polling to fetch, say every 15 minutes. But isn't "push" designed to only be active when something is there? Shouldn't that theoretically reduce battery drain?