There are several different ways you can approach your fitness training. When it comes to developing cardiovascular fitness, there are two major approaches. The first is long, steady, distance training, where you perform at a moderate intensity for an extended period of time. The other is interval training, where you alternate periods of rest with high-intensity exercise.
Interval Training Theory
Intense training burns more calories in a given time period than moderate-intensity training. According to interval training theory, exercising intensely offers more benefits -- more calories burned and increased cardiovascular fitness -- than exercising at a moderate rate for the same amount of time. To maximize benefits from intense training, train in intervals alternating intense intervals with periods of rest.
While interval training can be adjusted to almost any form of exercise, a rowing machine offers an excellent full-body workout. Proper rowing-machine form requires you to push with your legs and pull with your arms, while keeping your core strong as you straighten with each pull. Exercising with rowing machines builds your muscular and cardiovascular endurance.
One example of interval training is the Tabata protocol developed by Dr Izumi Tabata. Using the Tabata interval training method, even trained athletes can achieve significant gains. Regardless of your fitness level, use interval training by alternating 20-second periods of maximum intensity exercise with 10-second periods of rest. Eight sets of exercise and rest can produce results far beyond what you might consider possible during such a short time.
According to "Medicine and Science in Sports and Exercise," the official journal of the American College of Sports Medicine, a 205 lb. person burns 326 calories in an hour doing light work on a rowing machine, while rowing very vigorously burns 1,117 calories. You can reduce the length of your exercise time and achieve the same gains as you get from long periods of moderate-intensity exercise when you do interval training. Further benefits include after-burn -- increased caloric consumption -- according to sports conditioning coach John Berardi. You also burn additional calories to repair and replenish your muscles used in your workout..