Polar OwnZone Feature

The Polar OwnZone (OZ) feature determines an individual exercise zone. It guides you through an appropriate warm-up routine and automatically determines a safe and effective exercise heart rate zone - your OwnZone - while taking into account your current physical condition.

Polar Heart Rate Monitors use multiple methods for determining your OwnZone. The primary method is to measure your heart rate variability during the warm-up period before exercising. If the measurement is not successful, your latest saved OwnZone limits are used. If there are no previous limits in the memory, the Polar Heart Rate Monitor will automatically calculate OwnZone limits based on your age-predicted maximum heart rate (220 minus age). You should determine your OwnZone at the beginning of your workout whenever you change exercise environment and/or exercise mode or if your mental state changes when feeling stressed, for instance.

The OwnZone Basic corresponds to 65-85 % of the maximum heart rate. Exercise at the lower end of this intensity level can be conducted for extended periods safely and often yields the best results for weight control, while exercise at the upper end of this intensity produces the best results for improving cardiovascular (aerobic) fitness.

The OwnZone Advanced feature consists of two training areas: OwnZone Low and OwnZone High, providing greater variations in exercising than the OwnZone Basic area, which can be rather wide for more focused training.

The OwnZone Light corresponds to 60-70% of your maximum heart rate. This intensity still feels fairly easy for most people. It helps in weight control and improves endurance and cardiovascular fitness.

The OwnZone Moderate corresponds to 70-80% of your maximum heart rate. This intensity is especially good for people who are exercising regularly. Exercising in this zone is particularly effective for improving cardiovascular fitness.

The OwnZone Hard corresponds to 80-90% of maximum heart rate. You will find yourself breathing heavily, having tired muscles and feeling fatigued. This intensity is recommended occasionally for fit people.

The OwnZone Weight corresponds to about 60-75% of your maximum heart rate. The OwnZone Weight is ideal for weight loss exercise for less fit individuals and for those recovering from sickness or intensive training.

Safe and effective exercise intensity

For developing and maintaining cardiorespiratory fitness an exercise intensity of 55/65-90% HR_max has been recommended for healthy adults in the latest Position Stand of American College of Sports Medicine (ACSM 1998). The lower intensity values of the range are most applicable to individuals who are fairly unfit and higher exercise intensities are safe for more fit people. The recommended exercise duration corresponds to 20 min-1 hour repeated 3-5 times a week. The duration is dependent on the intensity; thus, low-intensity activity should be conducted over a longer period of time (30 min or more), and, conversely, individuals training at higher levels of intensity should train for at least 20 min or longer.

Polar OwnZone function automatically calculates the effective and safe intensity level for exercise. The determination is based on heart rate variability (HRV), and in the calculation either a HRV based method (OZ.V) or an age based method (OZ.A) is used.

HRV based method

The HRV based method calculates an individual training heart rate zone during graded exercise. Polar heart rate monitor with OwnZone feature guides the user with graphical bars on the display to start the exercise with slow walk and increase the speed to normal walk, fast walk, slow jogging and fast jogging. During OwnZone determination heart rate should be kept below 100 bpm and increased about 10 bpm at each of the following stage. OwnZone appears typically on the 3rd or 4th stage (in 5-6 minutes). This is done during a 2-10 minute warm-up routine recommended before any exercise session. The determination is based on a plateau of the heart rate variability decrease, which is a direct consequence of the increase in heart rate with exercise. This plateau is defined of the short term variable (Poincaré plot, SD1) of the heart rate variability and shown as lower and upper heart rate limits on the display.

OwnZone Basic

OwnZone basic (OZ basic) consists of one heart rate zone. The lower limit of the zone is based on the plateau of the heart rate variability decrease and corresponds to approximately 65% of the maximum heart rate. The upper limit of the zone is calculated by adding a fixed number of beats (30) to the lower limit, so that the upper limit of the zone corresponds to about 82% of the maximum heart rate. In cases where the heart rate variability during OwnZone determination does not decrease low enough or is too low to start with, the target heart rates are corrected by the % heart rate values calculated from the age predicted (220-age) maximum heart rate. The lower limit is not more than 80% HR_max and the upper limit is not more than 85% HR_max.

OwnZone Advanced

OwnZone advanced consists of two target heart rate zones; low (OZ Lo) and high (OZ Hi). The lower limit of the "low zone" is based on the plateau of the heart rate variability decrease and corresponds to approximately 65% of the maximum heart rate. The upper limit of the "high zone" is calculated by adding a fixed number of beats (40) to the lower limit of "low zone". "Low zone" and "high zone" are calculated by dividing this 40 beats into two equal zones, 20 beats each. "Low zone" corresponds to 65-78% of the maximum heart rate and "hard zone" to 78-87% of the maximum heart rate. In cases where the heart rate variability during exercise does not decrease low enough or is too low to start with, the target heart rates are corrected by the % heart rate values calculated from the age predicted (220-age) maximum heart rate. The lower limit of the "low zone" is not more than 80% HR_max, and the upper limit of the "high zone" not more than 95% HR_max.

Age based method

The age based method is used in the following cases provided that there has not been previous successful HRV based determination (OZ.L): too fast increase in the exercise intensity during warm-up, muscle artifacts or other disturbances, or abnormal autonomic nervous system response make it impossible to determine the plateau of the heart rate variability decrease.

The age based method uses the age predicted maximum heart rate formula (220-age). In the OwnZone basic the 65-85% HR_max target heart rate zone is calculated. In the OwnZone advanced for the "low zone" the 65-78% HR_max and for the "high zone" the 78-90% HR_max target heart rate zone is calculated. The heart rate monitor shows this on the display (OZ.A).

Benefits

The OwnZone feature offers a safe light to moderate intensity exercise zone determination individually. A laboratory measured maximum heart rate gives the most reliable basis for the target zone determination, but the HRV based OwnZone is more sensitive than the laboratory tests, because the user can repeat the determination as often as he/she wishes. This is needed, because maximum and submaximum heart rate responses change within individuals even daily. Heart rate is individual due to age, fitness level and gender. In addition, factors like the intensity and mode of exercise, environmental temperature, body position, state of mood and eating and drinking habits affect the heart rate response.

Using OwnZone feature

The OwnZone procedure can be repeated conveniently even in the beginning of every exercise session. It should be performed always when changing exercise environment and/or exercise mode or having abnormal feelings of physiological state at the start of the exercise. The heart rate monitor saves the latest OwnZone limits. Because the OwnZone basic area is rather wide (e.g. in a 20-year-old person, OZ.A at maximum 40 beats), the exercise intensity can be targeted either close to the lower or to the upper limit of the OwnZone basic. The "low" and "high" zones of the OwnZone advanced help the user to better meet the exercise intensity needed. The lower limit of the OwnZone basic and the "low zone" of the OwnZone advanced correspond to light, and at most to moderate exercise intensity. Exercise at this intensity can be conducted for extensive periods of time and often; daily and even several times a day. The exercise is targeted to health and weight loss-related exercise for sedentary and less fit individuals, for those rehabilitating from a disease or for athletes recovering from more intensive training. The upper limit of the OwnZone basic and the "high zone" of the OwnZone advanced correspond to moderate, and at most to hard exercise intensity, which typically targets to fitness benefits.


Reference

ACSM (American College of Sports Medicine). Position Stand: The recommended quantity and quality of exercise for developing and maintaining cardiorespiratory and muscular fitness, and flexibility in healthy adults. Med Sci Sports Exerc 30(6), 975-991, 1998.