Good lord. I took 5 years off. I applied after 3 and didn't get in. I applied after 5 and got in. I didn't have any problems with my requirements or the time lapse between my application and my courses. Of course, it did mean taking the MCAT again. But I actually scored 1 pt higher the second time around (after being out of UG for 3 years).
I've said it before, and I'll say it again. Taking time off is totally the way to go. I had some of the best times of my life during those years. And it wasn't spent in the library with my nose in a book. Now I feel that I am ready to buckle down and do just that. I got it out of my system.
Finally, and take this or leave it, but consider doing something else other than research. 1 year isn't a whole lot to learn much/do much damage. I'm sure there will be folks on here who will argue with me, "yes it is, I got a publication, blah blah blah" which is all well and good. But don't just do reearch to strengthen your application. A lot of applicants seem to do that, without really giving a damn about the project. I burned out just as quickly (if not quicker) in research as I did in UG.
Do research because you love the project, or because you want to learn a particular technique, or because you love being overworked and underpaid/underappreciated. If I had it all to do over again, I would've quit my research job much sooner and gone into biotech or consulting. (Or I would've been a ski bum for longer than 3 months.) Most of my friends who went into that line of work now own nice condos in downtown DC, and have plenty of free time and travel money.
But definitely take 1 or 2 (or more) years to do something you've always wanted to do. Preferably unrelated to medicine. There's always time for hospital volunteering/shadowing during the weeknights or weekends.
Of course, you're pre-med, so you'll end up doing research anyway, despite my warning. But, believe me, you'll kick yourself in a year for not doing something more lucrative, or random, or new.