Unfortunately, a tougher workout will not make you feel better sooner. In fact, an overzealous, vigorous workout on a day when you're feeling less than stellar can worsen your symptoms. When you're working with a hangover, it's best to stick with a light and steady cardio session on a treadmill or stationary bike, a restorative yoga class, or a brisk walk outdoors. The fresh air can do wonders when you're feeling under the weather and zapped of energy.
Most importantly, make sure you're continuing to hydrate before, during, and after any postparty workout. Once you've finished your session at the gym, give yourself time to relax and recover — that's the very best way to make sure you bounce back as quickly as possible.