Ruthi answered "swamped" well. "Saddle up" can also be a slang term for preparing yourself to do something big. So you might say "Saddle up, we have a big exam tomorrow!"

1.swamped means you have too much to do,and you can't manage to do all your work. 2. Saddle up usually means to prepare a horse to ride on it.However it may mean something else.Please provide a context, or sentence using the phrase in it.