Get the heart racing and the upper body pumped in this fat blasting workout. Our main man, Mark, has devised two brutal upper body circuits that will help build muscle, and burn fat in just one hour! The first circuit includes 6 exercises, in two sections. Each section includes short 15 second breaks between each movement, with a longer 75 second break to catch your breath in the middle. Repeat the circuit 4 times. The second circuit involves just…