Yet another great cardio machine, but this one doubles as an upper body workout at the same time. Rowing is probably the single best form of cardio--apart from swimming, of course! The beauty of rowing is that you don't need a massive pool to get in your workout, but all you need is the small indoor rowing machine. [caption id="" align="aligncenter" width="658"] Source: www.exerciseequipmentwarehouse.com[/caption] When you go through the motions of rowing, you put your entire body through a workout. Your core works as you lean backward, your legs work as you push back, and your biceps, shoulders, and back are shredded by the repetitive pulling motion. The only muscles that don't get a workout are your chest and triceps. So when you want to finish off Back and Biceps day in style, there's nothing better than the rowing machine for the perfect cardio/strength training combo. Plus, it's much more to row, rather than repeat the monotonous step, step, step of a treadmill. Bonus points for an epic full body workout!