PCCSylPoolOrca Image The New Nia Technique & Swish Logo PilatesLogo Yoga's Aoum
Updated: 20 September 2008

Cardio-Respiratory Capacity

Cardio-respiratory or aerobic fitness refers to the ability of the heart-lung system to deliver O2 to and remove CO2 from the working skeletal muscles during prolonged exercise activities.  The greater this ability, the higher the cardio-respiratory fitness level.  A low level of cardio-respiratory fitness is directly related to lack of exercise.  Regular exercise is a significant factor in reducing the severity of cardiovascular disease.  A regular exercise program leads to adaptive changes in the system to yield a higher cardio-respiratory fitness level.  To obtain an adaptive response of the cardio-respiratory system, demands must be made on the system that exceed those normally encountered.

Most experts recommend consideration of four factors to achieve beneficial results from exercise:

A number of methods have been developed to determine the appropriate intensity level.  The heart rate reserve or Karvonen method of calculating your target heart rate or training zone is based on your maximal heart rate (MaxHR) and resting pulse (RHR) and considered relatively accurate.  Easier calculated but less accurate is the method using only the age specific maximal heart rate.  Other methods include the Borg Scale of Perceived Exertion.  This method relies purely on your subjective feeling of how hard you think you are working.  This is especially helpful when the other methods can’t be used, e.g., when the exerciser has a condition that affects heart rate, e.g., takes certain medication or fights a disease causing agent.  With a little bit of practice it is surprising how much this scale can correlate with the actual HR computed using one of the other methods.  For heart rate calculation during  Exercise in the Water, subtract 13% or 17 beats per minute from the Target Heart Rate Zone calculated by above methods, as water temperature, gravity, compression, partial pressure and the dive reflex affect (reduce) heart rate.

To figure out your target training zone, determine your true resting heartrate:  Three mornings in a row, just after waking up  (preferrably without startling alarm), before sitting up or standing up, take your resting pulse for one full minute.  When counting beats, start with the first beat as zero: ie., 0-1-2-3-4....  Add all of them together, and divide by 3, to get the average.  For most healthy people it should be somewhere around 60 beats per minute.

Then apply the formula for the Karvonen method: so, for example I calculate for myself  J   thus:
(220) - (your age) = MaxHR220 - 25 = 195 (MaxHR)
(MaxHR) - (resting heart rate) = HRReserve195 - 60 = 135 (HRReserve)
(HRR) x (60% to 80%) = recommended training range % 135 x .6 = 81 (60% training percentage)
135 x .8 = 108 (80% training percentage)
(training range %) + (resting heart rate) = (your target training zone) 81 + 60 = 141 (low end target training zone, in beats per minute)
108 + 60 = 168 (high target training zone, in beats per minute)

So, my target training zone in beats per minute is between 141 and 168.  Of course, heart rate slows down immediately after cessation of vigorous exercise, so to get a more accurate count, take your pulse only for 6 (or 10) seconds, then multiply by 10 (or 6) to get your heart rate per minute.  Remember to start with the first beat as zero: ie. 0-1-2-3-4....

Another way of determining how hard you are working is the Borg Scale of Perceived Exertion.  Using your own subjective Rate of Perceived Exertion (RPE) on a scale of 6-20 or a scale of 0-10, you determine how hard you *feel* you are working.

Original Scale Revised Scale
6 0 - Nothing at all
7- Very, very light0.5 - Very, very weak
8 1 - Very weak
9 - Very light 2 - Weak
10 3 - Moderate
11 - Fairly light 4 - Somewhat strong
12 5 - Strong
13 - Somewhat hard 6
14 7 - Very strong
15 - Hard 8
16 9 - Very, very strong
17 - Very hard 10 - * Maximal
19 - Very, very hard 

Consider that the recommendation is to work out in your aerobic zone, which is, you should not work out too hard (in your anaerobic system).  For more detail to this see Chapter:  Energy Systems.

Go to the next chapter:  The Energy Systems of the Body
Go back to the  Table of Contents

Go back to Lia's SplashPage.
Created by Lia Kidoguchi.