Information about Polar Fitness Test and fitness testing in general
R&D and Marketing/Polar Electro Oy
Dec 7 2000
INFORMATION ABOUT POLAR FITNESS TESTTM AND FITNESS TESTING IN GENERAL
What is Cardiovascular Fitness?
Cardiovascular (or aerobic) fitness is one of the most important components of fitness. It is measured as the amount of oxygen in the blood pumped by the heart and transported to the working muscles and as the efficiency of the muscles to use that oxygen. Increasing cardiovascular fitness means increasing the capability of the heart and the rest of the cardiovascular system in their most important task, to supply oxygen and energy to your body.
Having good cardiovascular fitness has many health benefits. For example, it decreases your risk of cardiovascular diseases, stroke, high blood pressure and other diseases.
Cardiovascular fitness is best improved by activities, which employ large muscle groups working dynamically. Such activities include walking, jogging, running, swimming, skating, cycling, stair climbing and cross-country skiing.
The heart is like any other muscle - it becomes stronger and more efficient after practise. Heart rate is a quantitative measure of heart's work. At rest a healthy heart of an average individual beats approximately 70 beats per minute. A conditioned heart beats much less at rest, only 40 to 50 beats per minute or even less. Heart rate variability is a quality measure of heart's work. The lower the resting heart rate the higher the heart rate variability, and thus the better the quality of heart's functions.
Cardiovascular fitness is related to age, gender, exercise habits, heredity and cardiovascular clinical status. Maximum values occur between ages 15 and 30 years, decreasing progressively with age. At the age of 60, the mean maximal aerobic power in men is approximately three fourths of that at the age of 20. With sedentary lifestyle, there is a 10% reduction in the mean maximal aerobic power per decade, the reduction with an active lifestyle being less than 5%.
Fitness tests for aerobic fitness
There are numerous fitness tests for aerobic fitness in the world ranging from sophisticated laboratory tests to simple field tests. They are all designed to measure or predict oxygen uptake (maximal aerobic power, VO2max). Most of the predictive tests target to estimate the oxygen uptake of the body via heart rate and/or workload. Depending on how hard the body is exhausted during the tests, they can be divided into two categories: maximal tests and submaximal tests.
The most common maximal test procedures used for testing cardiovascular fitness are:
1. Maximal oxygen uptake test (on a treadmill or cycle ergometer)
2. Shuttle run test (Leger test)
3. Continuous run test for a fixed time or distance (Cooper test)
The most common submaximal test procedures used for testing cardiovascular fitness are:
1. Cycle tests (Åstrand test, WHO cycle test, PWC170 test)
2. Step tests (Harvard step test, Queens College step test)
3. Walking tests (UKK Walk test, Rockport Walk test)
Maximal tests have been designed for the needs of professional athletes rather than for those of non-competitive exercisers. Very seldom a normal, active man or woman has the possibility to costly and exhaustive laboratory tests.
Still, many of them are interested in their fitness. What is my fitness level? Do I need to start exercising? How to follow my improvement best? Can I see the improvement with my heart rate monitor?
Polar Fitness TestTM
Polar Fitness Test™ is a breakthrough in the world of aerobic fitness testing. It is developed to measure cardiovascular fitness based on the changes in your resting heart's beating, heart rate variability. Polar Fitness Test™ helps people to get information about their physical condition easily. They can now test fitness all by themselves, fully automatically and best of all, safely, without any exhaustion in less than five minutes.
Polar Fitness Test™ is based on an individual’s gender, age, height, body weight, the level of physical activity, heart rate and heart rate variability measured at rest. Once the first five items are given, the test can start. The duration is at maximum 5 minutes and the progress is displayed graphically. The person who is testing himself/herself should be at rest in a laying or sitting position. Any disturbances, such as talking during the test or surrounding noises, should be avoided.
Polar Fitness Test™ can be performed using the following Polar Heart Rate Monitors: M51/52/53/61/62, F92ti, M91ti, S210/410/510/520//610/610i/710/710i/720i/810, AXN500/700, RS200/400/800 and CS400/600. No other equipment such as treadmill is needed. No special facilities or testing personnel is needed either. Anyone can do the test by himself/herself or let the trainer or exercise physiologist to do it. The test can take place anywhere from home to office or to health club as long as the environment is peaceful. However, for maximal consistency and reliability it is recommended to keep the testing place, time of the day, body position and testing environment the same every time when the test is repeated.
Interpreting the test results
In every fitness test, you need to know what the given result means to benefit from it. In Polar Fitness Test™ the person gets a score, Polar OwnIndex™ (in M-series heart rate monitors) or Polar OwnIndexS TM(in S-series heart rate monitors), which is comparable to VO2max, a commonly used descriptor of aerobic fitness. Therefore the range for the Polar Fitness Index™ is the same as that for VO2max, from 25, which can be measured for unfit sedentary individual, to 95, which is the level reached by some Olympic athletes, such as top cross-country skiers. Fitness tests are most useful when following individual progress by comparing new results to previous ones.
National norms can be used to compare the test results to the average values of those with the same age and gender. For this comparison up-to-date results measured in a large sample of a representative population are needed. Below is one example of normal values presented as a mean and standard deviation values according to the age group (Fletcher et al. 1995).
Individual OwnIndex™/OwnIndexSTN can be compared to the population norms as follows: One standard deviation around the mean (half of SD up and half down) represents "average fitness". E.g. for a 33-year-old woman index between 31-37 (34-3 and 34+3) represents "average fitness" compared to other women of the same age. An index less than 31 is below the average and an index more than 37 is above the average.
Polar Fitness Test™ is an exceptional test because it measures your body's response in rest. This is unique since there is only one other aerobic fitness test, so called Non-Exercise Fitness Test (Jackson et al. 1990), which does not require exercise performance for fitness assessment. This test is incorporating physical activity and body mass index, BMI. The safety of the Polar Fitness Test™ can be fully guaranteed, which broadens the possibilities of using this test to persons who have previously been out of the reach of fitness testing due to health risks in exhaustion, for example the elderly and those with musculoskeletal disorders.
Not all individuals feel comfortable being measured by someone else or being compared with others. Polar Fitness Test™ can be conducted privately without participation into e.g. mass testing. Some people with low fitness level may be embarrassed about their poor physical condition and may wait for weeks before joining in an organised exercise program that includes testing in the beginning, just to avoid the humiliation. People should not be humiliated by test results of poor physical condition.
Monitoring the progress
It takes a minimum of 6 weeks on an average to see a demonstrable change in cardiovascular fitness. Less fit individuals see progress even more rapidly and for more active individuals more time is needed. The purpose of Polar Fitness Test™ is the same as for all fitness tests, to monitor this progress. For less active people it's a good idea to enter the more active world of health and fitness with the Polar Fitness Test™. For more active people, who have never been tested and who aren't really aware of the state of their fitness, it gives motivation to keep going. It rewards any fitness enthusiast to see the improvement with one's own eyes.
To be able to follow the progress you have to start with measuring the baseline. Polar Fitness Test™ gives you an excellent possibility to create this baseline. For example, if you decide today to start a regular fitness program the first thing you have to do is to conduct the Polar Fitness Test™. Let's assume it gives you an index of 40. This is now your baseline value.
A healthy adult can achieve a 10-15% change in cardiovascular fitness in 10-12 weeks when exercising at moderate intensity 3-4 times a week for at least 30 minutes each time. In our example this would mean an index increasing from 40 to 45 in 3 months. With Polar Fitness Test™ the progress can be monitored even weekly. However, the progress is slow and it is not the exact values, but rather the trend, that is the most important thing to follow. Losing body weight also increases the index.
Validity and reliability of Polar Fitness TestTM
Validity of a test means that the test measures what it is supposed to measure and not something else. The test has been originally developed using artificial neural networks on 305 laboratory fitness measurements of healthy Finnish men and women (Väinämö et al. 1996). The correlation coefficient between the laboratory measures and prediction values was 0.97 and the mean error in VO2max prediction was 6.5%.
In further development of the test 119 fitness measurements of healthy American men and women were included, making a total of 424 (Kinnunen et al. 2000), and the artificial neural network was modified into Polar Fitness Test™. In a study on 52 healthy men, who didn't belong to the group on whom the test was developed, the mean deviation in Polar Fitness Test™ prediction was less than 12% compared to the laboratory measures of maximal aerobic power. Thus the validity of the Polar Fitness Test™ is good.
The reliability of a test is a measure of how consistent and reproducible the test results are on consecutive trials. The reliability of the Polar Fitness Test™ is good. When 11 subjects repeated the test in the morning, in the middle of the day and in the evening during eight days, the average individual standard deviation of consecutive test results was less than 8% from the individual mean value. The standard deviations calculated separately for each time of the day were all smaller than the standard deviation of all results. This indicates that the test can be conducted at any time of the day but it should always be repeated at about the same time.
Polar Fitness Test™ was further developed to result OwnIndexSTM, an advanced modification of OwnIndexSTM. In the test development study, 450 laboratory fitness measurements of 15-65-year-old healthy men and women were performed. Correlation coefficient between the laboratory measured VO2max and OwnIndexSTM prediction in the data was 0.96 and the mean error in the prediction was 8.2% (3.7 ml/kg/min). Thus, the accuracy of the OwnIndexSTM is good and comparable to any other predictive tests, in which the mean errors vary between 8-15%. In the laboratory measurements of VO2max, the test-to-test variation within an individual is 3-5% due to physiological day-to-day variation and technical parameters. OwnIndexSTM was also validated in studies (Peltola et al. 2000, Tschopp et al. 2000) on trained subjects. It was shown that the VO2max prediction associated reasonably highly with VO2max measured in the laboratory in both men and women.
Polar Fitness Test™ provides an incentive to exercise and fitness improvement. It is an excellent motivational tool for anyone who wants to achieve his/her fitness goals.
Maximum heart rate prediction in Polar S-series
Maximum heart rate prediction (HRmax-p) is carried out simultaneously with Polar Fitness TestTM in S-series heart rate monitors. HRmax-p is based on resting heart rate, heart rate variability at rest, age, gender, height, body weight and maximal oxygen uptake, VO2max (measured or predicted). The HRmax-p score gives a more accurate estimation of individual HRmax than the age-based method (220-age) (Hannula et al. 2000).
ACSM (American College of Sports Medicine). The Fitness Book. 2nd ed. Human Kinetics. 1998.
Devereux R. Fitness testing - to do or not to do? Asiafit March/April 1998, p. 24.
Fletcher, Balady, Froelicher, Hartley, Haskell, Pollock. Exercise Standards. A statement for healthcare professionals from the American Heart Association. Circulation 91,2,580-615,1995.
Hannula, Nissilä, Kinnunen, Virtanen. Development of a new HRmax prediction model. Proc 5th Annual Congress of the ECSS, Jyväskylä, Finland, 19-23 July 2000, p. 306.
Jackson, Blair, Mahar, Ross and Stuteville. Prediction of functional aerobic capacity without exercise testing. Med Sci Sports Exerc 22,6,863-870,1990.
Kinnunen, Väinämö, Hautala, Mäkikallio, Tulppo, Nissilä. Artificial neural network in predicting maximal aerobic power. Med Sci Sports Exerc 32,5,1535,2000.
Peltola, Hannula, Held, Kinnunen, Nissilä, Laukkanen, Marti. Validity of Polar Fitness Test based on heart rate variability in assessing VO2max in trained individuals. Proceedings of 5th Annual Congress of ECSS, Jyväskylä, Finland, 19-23 July 2000.
Tschopp, Peltola, Held, Kinnunen, Hannula, Laukkanen, Marti. Traditionelle und neue Ansätze zur Schätzung der maximalen Sauerstoffaufnahme in Ruhe. Schweizerische Zeitschrift für Sportmedizin und Sporttraumatologie 48(2),58-63,2000.
Väinämö, Tulppo, Mäkikallio, Röning. An artificial neural network for human aerobic fitness approximation. Proc the International Neural Network ICNN, Washington DC, June 3-6, 1996, pp. 1939-1949.