The majority of gyms out there have Group Exercise classes. These range from Yoga to circuit-training class such as Les Mills BodyPump.
They will also burn a lot of calories and help you work muscle groups outside of your usual routine. It's important to do this - it's called "muscle confusion" and it works wonders.
So rather than blasting your pecs and bi's every day this week, try a class. I highly recommend Zumba, Les Mills BodyPump, and any spin class you can find. If you don't have a gym membership but do own a Kinect, pop in Dance Central 3. There's even a Fitness mode you can dance to.