Lesson 2: Fundamentals of a Walking Program
Measuring Intensity
The three measures you can use to determine your appropriate intensity are 1) Heart Rate 2)Rating of Perceived Exertion 3)The Conversation Test.
A helpful guideline, however, is that you should walk at about the speed you would walk if you had just enough time to make it to your destination. Let's say, for example, that you decide to walk to the post office. When you stroll there casually, it takes you about 20 minutes. But the post office is closing in 18 minutes, and you need to fill out a form. You will probably try to get there in 15 or 16 minutes which you know you can do fairly easily if you walk at a determined speed.
1) Heart Rate
The traditional method of measuring intensity is heart rate. When we exercise, our muscles need increased oxygen. Oxygen is carried in the blood. The lungs breathe in the oxygen, transfer it our red blood cells (hemoglobin), and then the blood goes to the heart. The heart is like central station and transports blood out to the rest of the body. The heart is a muscle. Each time it contracts (beats), more blood is sent out to the rest of the body through its network of arteries. That is why we can measure the heart rate, by taking the "pulse" at various arteries. The two most commonly used locations to measure pulse are the carotid artery (on either side of the trachea) and the radial artery (on the thumb side of your wrist).
If you are taking your own pulse, you will probably have to stop walking while you count. It is generally recommended that you count the beats in a 10 second period and multiply by 6. For simplicity, and to take a quick measurement, you can also count the beats in a 6 second period and multiply by 10. Alternatively, you may choose to purchase a heart rate monitor, which gives you a constant readout of your heart rate. Heart rate monitors will be discussed in Lesson 3.
So, what is your target heart rate? There are several methods to determine this, but the easiest is to take a percentage of your maximum heart rate. How do you know your maximum heart rate? The formula for the general population is subtract your age for 220. Recommendations from professional organizations such as The American Heart Association, the American College of Sports Medicine and the American Council on Exercise vary, but the range is between 50 to 85 percent of your maximum heart rate. If you have not been exercising, you should keep your heart rate toward the lower end, and if you are an elite athlete, you can keep your heart rate towards the higher end.
The one confounding factor in using maximum heart rate as a guide, is that it is just an average. There is quite a bit of normal variation (about 30 to 40 percent) within the population. In other words, if you are 40 years old, your calculated maximum heart rate is 180 beat per minute. But it would be quite normal to have a maximum heart rate of 150 beats per minute or 200 beats per minute. What this means is that you could be going at intensities too low or too high.
Therefore, it is often recommended that people use other methods which are based on subjective measures that are related to physical measures. These are discussed in the other two methods.
2) Borg Rating of Perceived Exertion (RPE)
The Borg Rating of Perceived Exertion (RPE), developed by Swedish physiologist, Gunnar Borg, is a measure of how hard it feels like you are working. It is based on physical factors such as how hard you are breathing, how much your are sweating, whether your muscles are burning, and how hard it feels like you're heart is beating. The scale ranges from 6 to 20. A rating of 6 means "no exertion at all" and a level of 20 means "maximal exertion." You should be aiming for a rating between 12 and 14 which means "somewhat hard."
If you multiply these numbers by 10, there is a very high correlation between RPE and heart rate, taking into account that people's heart rates will vary depending on age, fitness levels and whether or not they take medications.
3) The Conversation Test
This is the low-tech method, but works quite well. The right pace for a moderate intensity aerobic workout is one in which you can carry on a conversation. The conversation will be somewhat winded. You may breathe in between words in a manner like this, "I {breath} {breath} went to {breath} {breath} that new restaurant {breath}last night. And {breath} it was {breath} {breath} terrific.
