Polar Fitness Test with OwnIndex®

A fitness test that measures your aerobic/cardiovascular fitness at rest in just five minutes. The result, Polar OwnIndex, predicts your maximal oxygen uptake (VO_2max).

The Polar Fitness Test is a revolutionary way to test aerobic fitness. Gender, age, height, body weight, in addition to level of physical activity, heart rate and heart rate variability at rest are all factors influencing the test results. The OwnIndex ranges usually from 20 to 95 and is comparable to VO_2max, the golden standard of aerobic fitness.

OwnIndex is most meaningful when following changes in your fitness over a long period of time. Find out how fit you are for your age and gender by comparing your result to the global references listed in the Polar user's manuals.

With the Polar Fitness Test you can measure your aerobic fitness by yourself, automatically and without any exertion. No other equipment other than a heart rate monitor is needed. The Polar Fitness Test is as accurate in predicting the VO_2max as any submaximal fitness test.

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 transported in the blood and pumped by the heart 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 practice. 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, VO_2max). 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 tests)

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 Test™
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.

Test procedure
The components of the Polar Fitness Test are gender, age, height, and body weight of the person, the level of physical activity and heart rate as well as 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 herself/himself should be at rest in a laying or sitting position. Any disturbances, such as talking during the test or surrounding noises, should be avoided.

Test equipment
.No other equipment such as a 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, 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, which is comparable to VO_2max, a commonly used descriptor of aerobic fitness. Therefore the range for the Polar Fitness Index is the same as that for VO_2max, from 25, which can be measured for unfit sedentary individual, to 95, which is the level reached by 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™ 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.

Safety
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.

Privacy
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 prior to starting an organised exercise program that includes testing in the beginning, prefer to wait for weeks before joining in, 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.

An average change in cardiovascular fitness for adults is 12-15 % in 10-12 weeks if moderate intensity exercise has been conducted 3-4 times a week at least for 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 Test™
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, 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 absolute error 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, in both sitting and laying positions, 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™ provides an incentive to exercise and improve fitness. It is an excellent motivational tool for anyone who wants to achieve his/her fitness goals.

References
ACSM. The Fitness Book. 2^nd ed. 1998. Human Kinetics.

Devereux Rob. 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.

Jackson, Blair, Mahar, Ross and Stuteville. Prediction of functional aerobic capacity without exercise testing. Med Sci Sports Exerc 22,6,863-870,1990.

Väinämö, Tulppo, Mäkikallio, Röning. An artificial neural network for human aerobic fitness approximation. Proceeding of the International Neural Network ICNN, Washington DC, June 3-6, 1996, pp. 1939-1949.