One of the questions I have been repeatedly asked by those new to aerobic exercise is how to tell if they are getting the most from their efforts. They are unsure if they are at the ‘right’ heart rate to get the most effective aerobic benefits.
First, a brief explanation of what ‘aerobic’ exercise is and why it is so important to your health. Your body converts food into energy by two very different forms of metabolism. Aerobic – with oxygen, and anaerobic – without oxygen.
Anaerobic metabolism is the creation of energy through the burning of carbohydrates in the absence of oxygen. This happens when the lungs cannot supply enough oxygen to the blood to keep up with the demands from the muscles.
Anaerobic metabolism is most generally associated with short, very intense, forms of exercise, mostly with weight training or sprinting. Anaerobic metabolism is crucial to increasing muscle mass. This why you will hear from weight lifters that they do very little, if any, aerobic types of exercise.
The biology of aerobic and anaerobic metabolism is very complex and with very little research you can quickly become lost in the complexity without a degree in biology.
I am going to simplify this complex process as the vast number of people who are interested in improving their health are not necessarily interested in becoming biologists.
The primary fuels used by the body for energy are glucose and fatty acids, with protein used when the first two are depleted. The first two are burned by the body aerobically during most of our normal activity, including moderate exercise. When the activity intensity reaches approximately 80% of the maximum possible the body switches to anaerobic metabolism.
Aerobic metabolism is very efficient and produces few negative byproducts. This is not true of anaerobic metabolism which produces lactic acid which causes muscle pain and is the reason our muscles ‘burn’ after intensive weight training.
Aerobic metabolism is like burning natural gas, clean hot flame with little waste.
Anaerobic exercise is like burning old tires, with lots of thick sooty smoke. Which one do you think is better for your body?
As long as you can breath without gasping for air you are burning your fuel aerobically. There are different formulas for figuring out your ‘correct’ aerobic threshold. Look on the wall of most gyms and you will see one of these formulas on a chart comparing age with intensity.
These charts are clinical formulas based on countless measurements of people exercising at different rates to come up with an average. These numbers are good as a general indicator, especially when first beginning your exercise program.
Far more accurate is your own personal aerobic threshold and you can figure this out fairly easily. Your own personal number is the heartbeat you have when you first become breathless…when you can no longer tell someone your name without gasping for breath.
This is the level that you will get the most benefit from your efforts. Keep your heart rate a few beats per minute below the point where you are beginning to gasp for breath. You need to maintain this level for a minimum of 15 minutes to attain the benefits of aerobic exercise.
Clinical studies have shown that doing aerobic exercise at least 3 or 4 time a week will increase the left ventricle – the chamber of the heart that pumps the freshly oxygenated blood into the body – by 15% to 20%. It will do this in four to six weeks!
As you continue to train your body you will be able to do more work, or go longer without exceeding your aerobic threshold. This very positive feedback will be helpful in keeping your commitment to stay with your program. You will have proof that your efforts are having a positive effect.
Another very important benefit of aerobic exercise is that when you have substantially raised your heartbeat you are moving a lot of blood through the body. This improves the nutrient flow to the cells and helps to get rid of waste materials that accumulate during normal cell function.
It also helps to move hormones and other necessary complex chemicals produced by some cells for the benefit of other cells located throughout the body. The cardio-vascular system, and its health, is the single most important factor in your good health.
The author has been an aerobics instructor for 28 years. He has taught at privately owned fitness clubs, but has been mostly associated with the Y.M.C.A where he has been a Certified Group Instructor since 1980. He is currently developing web sites that deal with health and fitness related topics.
[http://www.sweatforhealth.com]
