Aerobic Exercise

Aerobic exercise is very important and it is very much necessary to be fit and fine.
Aerobic exercise can be any type of exercise that causes your heart rate to increase and makes you breath harder than normal.But don’t worry, you don't have to join any “aerobic” classes to benefit from aerobic exercise.
Aerobic exercise is a very useful tool in fat burning too. The body has two sources of energy : sugar and fat. Sugar or glycogen is stored in the liver and muscle and is the easiest from of energy for your body to use. Glycogen is the bodies preferred source of energy. Fat on the other hand, requires more work to be used as energy.
Why? The problem is that fat can be broken down only as long as oxygen is available. Oxygen must be present for your body to burn fat for energy, but not to burn glycogen. In the initial stages of exercise, oxygen is not available.
It can take minimum of 20 to 35 minutes of constant exercise before fat is fully available to the muscles as fuel. How efficiently your body burns fat will depend on your current condition.
Exercise, particularly aerobics, enhances the development of capillaries to the muscle which in turn improves the blood flow wherever it’s needed. With better blood flow and improved oxygen uptake by the muscles, your body becomes better adapted at building muscle.
This is the most leading reason why you shouldn't neglect the aerobic part of your training.
The difference between aerobic and anaerobic training
Running, cycling and swimming are aerobic activities whereas weightlifting, sprinting and boxing are anaerobic activities. During aerobic exercise, the heart rate rises, respiration increases and carbohydrates and fats provide working muscles with energy via oxidation. During anaerobic activity, the heart rate and respiration increase to a greater degree, but stored adenosine tri phosphate (ATP) and creatine phosphate serve as primary energy sources. As a result, lactic acid accumulates in the muscles and blood. Another way to understand the difference between aerobic and anaerobic work is to think in terms of duration and intensity. If you can do an activity for a relatively long time (at least 20 minutes), the energy will have to be light than moderate so that you can keep it up. This is considered aerobic. Exercising at a high intensity - so high that you can't continue at that step for more than a minute or two at a time - is aerobic. But no exercise or activity is 100% aerobic or anaerobic. Sprinting may be anaerobic, while marathon running is aerobic, but when long-distance runners sprint for the finish line, they're activating their anaerobic metabolism.
Heart and health benefits
Aerobic exercise has a lot of heart and and other health benefits. Aerobic activity offers a wide variety of benefits to overall fitness and health. The visual improvements are great, but the long term, more important advantages occur on the inside. Together with cardiovascular efficiency, metabolic changes will take you another step closer to achieving ultimate fitness. You know aerobic exercise causes your body to burn calories, a percentage of which come from fat, depending upon (among other things) duration and intensity. But did you know that you continue to burn fat even after your workout is over? After training, the body needs to replenish muscle glycogen, and fatty acids help to manufacture adenosine tri phosphate(ATP). Basically, fat is used to partially refuel the body for its next burst of energy. The more intense the exercise, the more the body has to replenish, and the more fat it will use to do just that. Now as far your heart goes, aerobic exercise lowers your resting heart rate, increases stroke volume and improves the efficiency of the heart. A trained heart doesn't have to work as hard to deliver blood to the various parts of the body and can pump more blood with each beat than an untrained one. Aerobic training can also lower blood pressure, which in turn decreases the risk of heart attack.
I recommend that your aerobics sessions should be at least 15 to 20 minutes in length. Although beginners should take it easy when first starting aerobic training. Beginners should start off doing 5 to 10 minutes of aerobic training and try to gradually increase the amount of time at every new workout when it feels comfortable to do so.

When doing aerobics training, shoot for training in your target heart range. In order to find this range, take the number 220 and subtract your age in years (for example, if your 32, it would be 220 - 32 = 188), then take that number and keep your heart rate within 60 to 80 percent of it (for example, take 188 x 60% = 113 beats per minute).