Who says a weight bench can’t be comfortable? Your couch is just the right size for supporting your upper back and head (keeping your hips lifted) while you do exercises like chest presses. By only resting your upper body on the couch, you’ll engage more muscles—especially in your core—than you would doing the same moves with your full body on the bench. And more muscles working at once means more calories burned!
To do it: Grab a pair of dumbbells and get into position, resting only your head and shoulders on the couch. Your knees should be bent 90 degrees, feet flat on the floor hip-width apart. Bend your elbows 90 degrees so that they're straight out from your shoulders. Extend arms up, bringing weights together above your chest. Bend your elbows to return to the starting position. Do 3 sets of 10-12 reps. Be sure to use a weight heavy enough to challenge your chest by the last few reps of each set.