Tests That Measure Cardiovascular Fitness ________________________________________________________________________________________________________________
The most valid method used to determine your cardiovascular fitness is Maximum Oxygen Consumption (MOC). Maximum oxygen consumption is an exercise test that assesses the capacity of the circulatory system to transport oxygen. In short, the Maximum oxygen consumption measures your VO2max. That is, the greatest volume of oxygen that you can consume at once before you collapse. However, this method is impractical for use by the general public because it requires expensive equipment, trained administrators and considerable time. Because of these limitations, several efforts have been made to develop a field test that would correlate highly with maximum oxygen consumption. To date, the 12 Minute Run-Walk Test developed by Kenneth Cooper is one of the best field tests used to measure cardiovascular endurance because of its high correlation (.94) with the MOC test. This is the test we will focus on because it is practical and easily administrated. It might be noted that there are other clinical tests such as the Ohio State Step Test, the Modified Ohio State Step Test and the Harvard Step Test, which can be used to measure cardiovascular fitness. However, as with maximum oxygen consumption tests, these tests require a special laboratory setting. Incidentally, the Harvard Step Test, which was used extensively during the late 1960’s and early 1970’s to measure the cardiovascular fitness of college students, is a poor measure of cardiovascular endurance…so much for those brainy people at Harvard. In fact, the Harvard Step test correlates about .67 with MOC. That’s not good…actually it’s terrible. You would need a correlation of at least .90 to use the test interchangeably. The modified Ohio State Step Test correlates the highest (.96) with the MOC, but as indicated, it requires too much equipment to be of practical use for the general public. That leaves us with the 12 Minute Run-Walk Test.
- The 12 Minute Run-Walk Test The twelve minute run walk test consists of running and/or walking as great a distance as you can in a twelve minute period. The test is usually administered on a 440 yard track. However, it can be administered on any level field that has been measured for distance or a treadmill. For use of the treadmill, you will just have to do some fancy math to convert your mileage to the number of laps completed. Your score is the total number of laps covered in the twelve minutes. Researchers who developed this test develop norms for various levels of fitness. So, depending on what your heart rate or performance time is for the test, you can compare your fitness level with thousands of others who have also taken the test. Norms published by Cooper (1968) for the test are presented in Table 1.
Category Poor Poor Fair
TABLE I Sex 13-19 Years 20-29 Years 30-39 Years less than 5.6 less than 5.3 less than 5.2 Male laps laps laps less than 4.7 less than 4.5 less than 4.2 Female laps laps laps 5.3 to just 5.6 to just less 5.2 to just less Male less than 6.0 than 6.2 laps than 5.8 laps laps 4.5 to just 4.7 to just less 4.2 to just less Female less than 4.9 than 5.2 laps than 4.7 laps laps
40-49 Years less than 5.0 laps less than 3.9 laps
5.0 to just less than 5.6 laps
4.7 to just less than 5.2 laps
3.9 to just less than 4.5 laps
3.5 to just less than 4.2 laps
less than 4.7 laps less than 3.5 laps
Good Excellent Excellent
6.0 less laps 4.9 5.2 to just less Female less than 5.7 laps laps 6.9 or more 6.6 Male laps laps 5.7 or more 5.4 Female laps laps Male
6.2 to just less than 6.9 laps
to just than 6.6 to just than 5.4
5.8 to just less than 6.3 laps
5.6 to just less than 6.2 laps
5.2 to just less than 5.8 laps
4.7 to just less than 5.2 laps
4.5 to just less than 5.0 laps
4.2 to just less than 4.8 laps
or more 6.3 or more 6.2 or more laps laps or more 5.2 or more 5.0 or more laps laps
5.8 or more laps 4.8 or more laps
As previously mentioned, this test is not only highly reliable (individual's scores are consistent when retested), it is more importantly, a valid indicator of cardiovascular fitness. Validity means that it is actually measuring cardiovascular fitness when it says that it does (unlike the guys at Harvard). There are, however, several drawbacks to this test. Some individuals do not have sufficient motivation to put forth the strenuous effort required to complete the test. In addition, there is a danger of cardiorespiratory complications…especially in individuals who are not accustomed to intense exercise.
- The 600 Yard Run-Walk Test The 600 Yard Run-Walk Test was field test devised in 1956 by the American Association of Health, Physical Education, Recreation and Dance (AAHPERD) Council on Fitness. Currently, the test is being used in many schools in the United States as a measure of cardiovascular fitness. Research has indicated that the 600 yard run-walk test is a valid measure for very young children. For older children and adults, unfortunately, research has yielded low correlations between this test and tests of maximum oxygen consumption. The 600 yard run-walk test, in contrast to the more valid 12 minute run-walk test, does not require enough activity to sufficiently tax the cardiovascular system of older individuals. Consequently, the test is not a valid indicator of fitness for adults.
Training for Cardiovascular Fitness The Cardiovascular Training Sensitivity Zone ________________________________________________________________________________________________________________________________________
Once you have evaluated your cardiovascular fitness, the next step is to develop more of it…that makes sense…right? An individual will show cardiovascular improvement (training effect) only if his heart rate is elevated to the proper level and maintained at that level for an adequate period of time. The training sensitivity zone refers to the range of heart rates that, if maintained, would result in cardiovascular benefits. The upper limit of the zone is the maximum heart rate of the individual (estimated to be 220 minus the individual’s age). Although different experts recommend slightly different values, 70% of maximum heart rate is usually taken to be the lower limit of the zone. For example, if you were 20 years of age, you would subtract your age (20) from 220 and then take 70% of that to ascertain the lower limit of your training sensitivity zone (220-20=200x.70=140). This is the heart rate at which you would have to exercise in order to get a minimum cardiovascular training effect. Here is more good news, we are being a little bit vicious here, not only do you have to elevate your heart rate to at least the lowest limits of your training sensitivity zone, but you have to keep it there for an extended period of time. Most researchers suggest that approximately 10 to 15 minutes is necessary to get a training effect. In short, if you are 20 years old, you have to elevate your heart rate to 140 beats per minute and keep it there for approximately 10 to 15 minutes to get a training effect.
You can engage in any activity you want to achieve your training heart rate. Such activities like swimming, tennis, handball, bicycling, basketball, marathon sex, (see the possibilities are endless) Jane Fonda aerobics, yes, even Richard Simmons aerobics can be used. As long as you elevate your heart rate sufficiently and keep it in the training sensitivity zone long enough, you can get a training effect. Needless to say, you should choose activities that you enjoy. It should also be understood that, if these conditions They are generally moving at a snail’s pace. Very impressive! Sure, they are burning energy (calories), but as far as cardiovascular training goes, what they are doing is absolutely worthless for strengthening the heart. Any activity can be used to help you to maintain your body weight, but not all activities will develop cardiovascular fitness. Remember, you have to get into that training sensitivity zone and stay there if you want to get a cardiovascular training effect. It’s not easy. The old cliché, “No pain, no gain” certainly applies here. You have to struggle and sweat a little if you want to get some development or improvement. It should be noted that as with muscular strength and endurance, you will need to adhere to both the overload and progressive resistance principles that we talked about in chapter 3, when training for cardiovascular fitness. In brief, in order to improve cardiovascular fitness, the heart and muscles must be overloaded or stressed beyond what they are normally accustomed to. Also, to become more and more physically fit, you must systematically increase the resistance of the exercises. Each higher level of fitness requires a greater workload, meaning that, if you want to be great, you have to continually push yourself. Also, as indicated, these adaptations to workloads have to be developed chronically, which means over time. Don’t fool yourself into thinking that you can adapt to a certain workload in a day or a in a week. Actually, for a person who is completely untrained, they won’t see significant gains initially. However, as they progress to higher and higher levels of fitness, adaptations will likely occur much more slowly, requiring weeks or months to acquire a new level of fitness. You must tax your cardiorespiratory system in order to be receiving real fitness gains. You might compare these chronic adaptations to that of a person who is learning a new skill for the first time. The ∞ WELLNESS FOR LIFE ∞ __________________________________________________________________ “beginner” is likely to see huge improvements in the beginning, but the performer will plateau at a given Heart Rate as a Measure of Cardiovascular Fitness. level of proficiency or attainment. Subsequently, the body will resist any more changes unless the We’ve already discussed heart rate in the discussion about changes are sustained over time. cardiac output. So, you remember that the Heart rate is the From a motivational standpoint, perhaps number of times the heart beats per minute. Average normal the most important aspect of all this is that you heart rate is 60-80 beats per minute (bpm). Generally speaking, choose activities that you enjoy and are likely to an athletic individual has a lower resting heart rate than an continue. Remember, if you don’t stick to it, the untrained individual. You would think that a person with a lower heart rate at rest would be in better shape than a person with a training effect deteriorates rapidly. So, we’re higher heart rate at rest. going to suggest several different training methods Although some researchers have used resting heart rate that you might want to experiment with. as an indicator of cardiovascular fitness, recent research has Again, note that the best way to increase indicated that resting heart rate is not a valid measure of cardiovascular fitness is to engage in activities that cardiovascular fitness. The major reason for this is that resting are high intensity for an extended period of time. heart rate can be effected by so many variables. For instance, The general rule is that in order to get a stress, lack of sleep, or drinking a small coke or cup of coffee cardiovascular training effect you have to elevate can significantly elevate your heart rate. Consequently, an your heart rate to your training sensitivity zone individual who is in great cardiovascular shape may register a high resting heart because of some other intervening variable. and keep it there for ten to fifteen minutes. Need we say that will make you sweet a little, if you are
a woman of course you won’t sweet, you will glisten…RIGHT! All the exercise we are going to talk about here can be performed at low, medium or high levels of intensity. It might be noted that you can perform any exercise you desire…swimming, rope jumping, kickboxing, whatever…as long as you are getting a cardiovascular training effect. Of course, all exercise will burn calories, but once again, you have to elevate your heart to your training sensitivity zone and keep it there for 10 to 15 minutes if you want a cardiovascular training effect. In other words, it’s your choice…you can either be Monique or Halle Berry. These are tough choices to make in life.