Aerobic Exercise, What Good Effect It Has To Your Body?

Heavy Breathing

Aerobic exercise means “exercise that is intended to improve the efficiency of the cardiovascular system in absorbing and transporting oxygen”. It is also called ‘cardio’, for cardiovascular. Aerobic exercise refers to any cardiovascular activity that is rhythmical in nature, involves the legs (largest muscle group) and can be sustained continuously for long periods of time (20 to 60 minutes). Walking, jogging, cycling, stair climbing and rowing are a few examples.

It is essential for health and life extension as it provides the following benefits:

decreased blood pressure
decreased blood cholesterol
lowered resting heart rate
increased aerobic capacity
weight control
improved circulation

In addition, aerobic exercise is the only exercise that burns fat directly. For fat to be burned, oxygen must be present, and this only occurs during sustained aerobic exercise.

Before you start any fitness program, it is important to determine your own individual goals.

If your exercise goal is to do the minimum possible for health and longevity – for instance, if you already have a baseline of fitness, or if you are already at your goal weight – you can get away with ‘maintenance’ cardio (see below).

If your goal is fat loss, you will need to do more – see ‘fat-burning’ cardio below.

The secret is to do as much (or as little) cardio as it takes to reach and maintain your personal goals.

‘Maintenance’ cardio

20-30 minute sessions 3 times a week at a moderate intensity is enough to achieve the benefits listed above. 3 times a week is the minimum cardiovascular activity everyone should do, no matter what your goals. See below for how to determine ‘intensity’.

‘Fat-burning’ cardio

Reducing calorie intake alone is not an efficient strategy for losing weight. It also has side effects that are detrimental to your long-term health, such as slowing down your metabolism and setting you up for the yo-yo dieting syndrome (see the e-book Ultimate Health for more on this). If your goal is to lose weight, aerobic exercise is the best fat-burning strategy there is – much more so than simply reducing calorie intake. In fact, dieting without exercise is one of the major reasons for the 95% failure rate of weight loss programs today. The reason is simple – a decrease in calorie intake, if prolonged, slows down the metabolism while an increase in activity can speed up your metabolism.

The more cardio you do, the more fat you will burn. The higher the intensity of cardio, the more fat you will burn. The secret is to raise the heart rate into a certain zone and maintain it within this zone for extended periods of time. This zone is called the ‘fat-burning’ or ‘target’ zone (see below).

For fat loss, you will need to do 4-7 sessions of cardio a week, 30-60 minutes per session, at medium to high intensity. It is very important, once you have reached your ideal weight or body fat percentage, to cut back to 3-5 times a week, as your body will get used to the level of exercise and you will have to keep increasing just to maintain.

The ‘target’ zone

In order to improve your fitness and lose weight, you need to raise your heart rate to a certain point, and keep it there for the duration of your exercise session. If you do not raise your heart rate into this zone, you will not burn a significant number of calories. If you exercise above this zone, it becomes difficult to maintain the pace for a long enough time to be effective in burning fat (and you become more prone to overuse injuries). This point or range is known as the ‘fat-burning’ or ‘target’ zone. There are a number of ways to calculate your own target zone. You can get it done professionally at a gym (where your maximum heart rate is determined by making you exercise on a cardio machine until you drop!). This is the most accurate method as all the others are estimates, using the rule of ‘averages’ – and of course, no individual is the same! Here are 2 methods you can use if you cannot get it measured professionally.

The Age-predicted method

The estimated maximum heart rate is 220 bpm (beats per minute) minus your age.

For example, if you are 40, your estimated maximum heart rate is 220-40=180. (It could of course vary, depending on your base level fitness, genetic makeup etc. But this is a generally a good estimate that will be accurate for about 70% of people, and adequate for 90%.)

The target zone is 70%-85% of your estimated maximum heart rate.

So you need to train between 180x0.7=126 bpm and 180x0.85=153bpm. ‘Moderate intensity’ would be around 126 and above, ‘high intensity’ would be around the 153 mark.

The Breathing method

This is actually a very good way to determine whether you are in your target zone or not. You are in your target zone when you are breathing heavily, but not gasping for air. You can speak in full sentences without having to stop and catch your breath. If you are so out of breath you can’t hold a conversation (albeit uncomfortably!) you are above the target zone. Generally speaking, the harder you are breathing, the harder you are working and the more fat you will burn – provided you can sustain the activity for the required length of time. If you’re not breathing hard, you're not working out hard.

Measuring your heart rate

The ultimate way to measure your heart rate during exercise is with a heart rate monitor. This consists of a strap worn around your chest and a wrist monitor/watch and is very useful, especially for interval training (see below).

Another method is to use 10-second pulse counts. Before your workout, determine your 10-second count by dividing your target heart rate by 6. So using the example above, your target zone is 126-153 bpm. Divide 126 by 6 to get the low end of your target zone: 21 beats or pulses per 10 seconds (place your fingertips on your wrist or the side of your throat to measure). The high end of your target zone will be 153 divided by 6: 26 beats per 10 seconds. Try to keep in this range when you are exercising, for maximum fat burning.

The myth of ‘low intensity for fat-burning’

Exercising below your target zone does not burn a significant number of calories, which is why you need to get your heart rate into that zone for fat loss.

There has been a myth pervading the industry for years, that exercising above the target zone does not burn a significant number of calories. So everyone started promoting low-intensity aerobic exercise for a long duration as the best way to lose fat.

The truth is that at lower intensities you burn a greater percentage of calories from fat than carbohydrates, and at higher intensities you burn a greater percentage of calories from carbohydrates than from fat. High intensity aerobic exercise can burn as much as 65% of the body’s energy needs in the form of carbohydrate. However, the most important issue for fat loss is not the ratio of fat to carbohydrate burned, but the total number of calories burned and high intensity aerobic exercise burns the most calories! The lower the intensity, the lower the total number of calories burned and the higher the intensity, the greater the number of calories burned. High intensity cardio exercise also raises your metabolic rate after the workout to a much greater degree than low intensity cardio. That’s why high intensity is better – provided you maintain it for a long enough duration to burn a significant number of calories.

Increase the fat-burning effects of cardio by up to 300%!

Any time of day that suits your schedule is good for cardio, as long as you do it. However, many bodybuilders and fitness models believe that early morning cardio before eating burns the most fat. Although this is still debatable, the evidence is strong and it is worth considering doing your cardio first thing in the morning on an empty stomach if you are trying to lose fat. Here are some of the reasons given:

There is less glucose available in your bloodstream after not eating for 8-10 hours, so you burn more fat.
Eating causes a release of insulin. Insulin interferes with the metabolization of fat. Less insulin is present after not eating, so more fat is burned.
If you eat just before a workout, your body first burns off what you have eaten before it burns fat.
When you do cardio, your metabolism stays elevated for a period of time after the workout. If you do cardio in the evening, your body doesn’t utilize this period as effectively, as your metabolism drops dramatically when you sleep.
Morning cardio energizes you and wakes you up. It gives a sense of accomplishment and makes you feel great all day as it releases mood-enhancing endorphins.
It can help regulate appetite.

And of course, you’re less likely to skip your workout in the morning than after work when all your friends are off to the pub. And you can always set your alarm clock earlier to make time for exercise.

Interval training

Interval training is a fantastic secret to improving your fitness rapidly and to burning fat quickly. It is definitely not for beginners and should only be used when you have a base level of fitness. It is a technique you should use as well as steady state cardio training, not exclusively.

It consists of alternating half- to 2-minute periods of very high intensity cardio with half- to 2-minute periods of medium to low intensity or recovery cardio. During the high intensity period, you push yourself outside of your target zone (above 85%) to the point where you begin to lose your breath. You then reduce the intensity enough during the recovery interval so you reclaim the oxygen debt just in time to do another high intensity interval.

This method of training ‘teaches’ your heart to recover quickly after a period of exertion. One of the main things tested in fitness tests is how quickly your heart rate drops back to normal after exercise.

Interval training also has a marked effect on your metabolism after the workout. Your metabolic rate stays elevated much longer than after steady state cardio – which means you burn calories for longer after the workout is over. While it is not a huge difference, over time, it certainly adds up!

Again, do what works for you and what you can manage. The ‘work’ and recovery periods don’t have to be the same length of time. When you start, you may want to do 30-second work period followed by 1 minute recovery. Or 1 minute work, 2 minutes recovery. As you get fitter, change the length of the periods. Aim to do between 12-20 minutes of intervals. Be sure to warm up before (10-20 minutes of moderate cardio) and cool down afterwards.

With all exercise, keep your goals in mind. It is not necessary to keep on increasing your workouts. Do the minimum that will achieve the results you want.