A shocking 77.1 percent of Americans don’t get enough exercise. This is one of the leading causes of the 160 million obese or overweight individuals in the country. The good news is, by adding just 30 minutes to an hour of cardio exercise to your routine a few days a week, you can reduce your likelihood of joining these statistics. If you are a bit hesitant to begin high-intensity training, don’t worry, you don’t have to go full throttle right away. A great source of cardio exercise is a rowing machine workout.