Cardio exercises are of two types: (i) low-intensity, low-impact exercises such as walking, cycling, jogging and swimming and (ii) high-intensity, high-impact exercises – such as running, spinning, stair climbing and high-speed aerobics. Though both these types of exercises help in burning body fat, you need to choose the type of exercise that's most suited and most effective for your body.
Scientific research has shown that during high-intensity exercises the body's energy requirements are met with primarily by burning glycogen (a form of carbohydrate stored in the liver) as a fuel rather than fat. While it is indeed true that body burns much more fat during low-intensity exercises, it is only while performing high-intensity cardio exercises that the body burns a substantial number of calories, a part of which come from fat too. Thus, the benefits of low-intensity exercises cannot be expected to be as pronounced as the high-intensity cardio exercises. Take a look around you and see the number of people who are working out but still fat – you can bet your shirt that most of them are into low-intensity cardio exercises, which are not helping them much.
High-intensity cardio exercises pump up the body's metabolic engine. A high metabolic rate ensures that the body burns fats even when you are sleeping! Low-intensity cardio workouts do help, but do not boost your metabolism to those high levels. There is another factor that works in favor of high-intensity cardio exercises – when your stored glycogen level becomes low, the carbohydrates from your food readily convert to glycogen to make up for the loss rather than being stored as body fat, giving high-intensity cardio exercises a double-edged benefit.
There is a new kind of cardio exercise called "interval training". Interval training is nothing but periodically moving up from a low-intensity cardio workout to a high-intensity one and vice versa – for example: walk for 5 minutes, then break into a jog and continue doing so for the next 5 minutes; then cool down to brisk walking and again run fast for 1–2 minutes. Continue this low–high–low cycle for 15 or 20 minutes, finally ending it up with the regular, slow walk. The low-intensity phase allows you to catch your breath after the high-intensity phase.
Cardio exercises pump your body with vigor and energize your muscles. Obviously, they also help burn body fat and achieve a lean look.
If you've never tried cardio exercises before, you should give them a shot. Once you get into the groove, you'll find that cardio exercises, especially the high-intensity ones, are the best way to boost energy levels and stay in shape. If you are a beginner, then start with the low-intensity cardio workouts and graduate to the high-intensity ones once you feel more confident of taking them on. Good luck.
