Polar sport zones, as used on Polar RS200, Polar RS800, RS800CX, RS800G3 and RS800SD, introduce a new level of effectiveness in heart rate-based training. Training is divided into five sport zones based on percentages of maximum heart rate. With sport zones, you can easily select and monitor training intensities.

Target zone	Intensity % of HRmax, bpm	Example durations	Training benefit
MAXIMUM	90–100% 171–190 bpm	less than 5 minutes	Benefits: Maximal or near maximal effort for breathing and muscles. Feels like: Very exhausting for breathing and muscles. Recommended for: Very experienced and fit runners.Short intervals only, usually in final preparation for short running events.
HARD	80–90% 152–172 bpm	2–10 minutes	Benefits: Increased ability to sustain high speed endurance. Feels like: Causes muscular fatigue and heavy breathing. Recommended for: Experienced runners for all year round training in varying length.Becomes more important during pre competition season.
MODERATE	70–80% 133–152 bpm	10–40 minutes	Benefits: Enhances general training pace, makes Moderate intensity efforts easier and improves effiency. Feels like: Steady controlled fast breathing. Recommended for: Runners progressing towards events or looking for performance gains, particularly for half and full marathon training.
LIGHT	60–70% 114-133 bpm	40–80 minutes	Benefits: Improves general base fitness, improves recovery and boosts metabolism. Feels like: Comfortable and easy, low muscle and cardiovascular load. Recommended for: Everybody for long training sessions during base training periods and for recovery exercises during competition season.
VERY LIGHT	50–60% 104–114 bpm	20–40 minutes	Benefits: Helps to warm up and cool down and assists recovery. Feels like: Very easy, little strain. Recommended for: For recovery and cool-down exercises throughout the training season.

HR_max = Maximum heart rate (220-age).Example: 30 years old, 220–30=190 bpm.

Running in sport zone 1 is done at a very low intensity. The main training principle is that your performance level improves during recovery after training, not only during training. You can accelerate your recovery process with very light intensity training.

Sport zone 2 is for endurance training, an essential part of any training program. Running sessions in this zone are easy andaerobic. Long-duration training in this light zone results in effective energy expenditure. Progress will require persistence.

Aerobic power is enhanced in sport zone 3. The training intensity is higher than in sport zones 1 and 2, but still mainly aerobic. Training in sport zone 3 may, for example, consist of intervals followed by recovery. Running in this zone is especially effective for improving the efficiency of blood circulation in the heart and skeletal muscles.

If your goal is to compete at top potential, you will have to train in sport zones 4 and 5. In these zones, you run anaerobically, in intervals of up to 10 minutes. The shorter the interval, the higher the intensity. Sufficient recovery between intervals is very important. The training pattern in zones 4 and 5 is designed to produce peak performance.

The Polar sport zones can be personalized by using a laboratory measured HR_max value, or by taking a field test to measure the value yourself. When running in a sport zone, try to make use of the entire zone. The mid-zone is a good target, but keeping your heart rate at that exact level all the time is not necessary. Heart rate gradually adjusts to training intensity. For instance, when crossing from sport zone 1 to 3, the circulatory system and heart rate will adjust in 3-5 minutes.

Heart rate responds to exercise intensity depending on factors such as fitness and recovery levels, as well as environmental, factors. It is important to look out for subjective feelings of fatigue, and to adjust your training program accordingly.

After the exercise, exercise duration is displayed in sport zones. Access the Weekly display to see in which sport zones you have been exercising, and the duration spent in each sport zone.

The Polar ProTrainer 5 offers up to 10 sport zones to better serve your training needs and heart rate reserve.

Your running computer determines automatically an individual and safe exercise intensity zone: your OwnZone. The unique Polar OwnZone defines your personal training zone for aerobic training. The function guides you through your warm-up, and takes your present physical and mental condition into account. For most adults, OwnZone corresponds to 65-85% of maximum heart rate.

OwnZone can be determined in 1-5 minutes during a warm-up period by walking, jogging, or doing some other sport. The idea is to start exercising slowly at a light intensity, and to gradually increase intensity and heart rate. OwnZone is developed for use by healthy people. Some health conditions may cause heart rate variability-based OwnZone determination to fail. These conditions include high blood pressure, cardiac arrhythmias, and certain medications.

Listening to and interpreting the signals your body sends during physical exertion is an important part of getting fit. Since warm-up routines differ for different types of exercise, and since your physical and mental state may also vary from day to day (due to stress or illness), using the OwnZone function for every session guarantees the most effective heart rate target zone for that particular type of exercise and day.

Maximum heart rate (HR_max) is the highest number of heartbeats per minute (bpm) during maximum physical exertion. It is individual and depends on age, hereditary factors, and fitness level. It may also vary according to the type of sport performed. HR_max is used to express exercise intensity.

Determining Maximum Heart Rate

Your HR_max can be determined in several ways.

If you have done some hard training in recent weeks and know that you can safely reach maximum heart rate, you can safely take a test to determine your HR_max yourself. Having a training buddy with you during the test is recommended. If you are uncertain, consult your physician before undertaking the test.

Here is an example of a simple test.

Step 1: Warm up for 15 minutes on a flat surface, building up to your usual training pace.

Step 2: Choose a hill or stairwell that will take more than 2 minutes to climb. Run up the hill/steps once, building to as hard a pace as you can hold for 20 minutes. Return to the base of the hill/steps.

Step 3: Run up the hill/steps again, building towards a pace you could just about hold for 3 kilometers. Note your highest heart rate. Your maximum is approximately 10 beats higher than the noted value.

Step 4: Run back down the hill, allowing your heart rate to drop 30-40 beats per minute.

Step 5: Run up the hill/steps once again at a pace that you can only hold for 1 minute. Try to run halfway up the hills/steps. Note your highest heart rate. This brings you close to your maximum heart rate. Use this value as your maximum heart rate to set training zones.

Step 6: Make sure you get a good cool-down, a minimum of 10 minutes.

HR_sit is your average heart rate when completely still (i.e. while sitting). To easily determine HR_sit, wear your transmitter, sit down, and do not engage in any physical activity. For a more precise measurement, repeat the procedure several times and calculate your average.

Heart rate reserve (HRR) is the difference between maximum heart rate (HR_max), and resting heart rate (HR_rest)*. HRR is used to calculate exercise heart rates. It is the range within which heart rate varies depending on exertion level. HRR equals oxygen uptake reserve (VO₂R).

Exercise heart rate can be determined by using the Karvonen formula**. Add the given percentage of heart rate reserve to resting heart rate.

Exercise HR = % of target intensity (HR_max – HR_rest) + HR_rest

Example:

Target intensity 70 % HRR for a person with HR_max 201 bpm and HR_rest 50 bpm

Exercise HR= 70% (201-50) + 50

Exercise HR=156 bpm

For a precise exercise heart rate, you need your exact HR_max and HR_rest. When using estimated HR_max, exercise heart rate values are always estimates.

*In Polar RS400 and RS800 running computers, the heart rate value during a resting state is measured in a sitting position (HR_sit). This is for practical reasons since HR_sit is used in energy expenditure calculation because of accuracy. HR_sit matches the low intensity to which different exercise intensities can be compared.

**Karvonen M, Kentala K, Mustala O. The effects of training on heart rate: a longitudinal study. Ann Med Exp Biol Fenn 1957; 35: 307-315.

Heart rate varies with every heartbeat. Heart rate variability (HRV) is the variation of beat to beat intervals, also known as R-R intervals.

HRV indicates the fluctuations of heart rate around an average heart rate. An average heart rate of 60 beats per minute (bpm) does not mean that the interval between successive heartbeats would be exactly 1.0 sec, instead they may fluctuate/vary from 0.5 sec up to 2.0 sec.

HRV is affected by aerobic fitness. HRV of a well-conditioned heart is generally large at rest. Other factors that affect HRV are age, genetics, body position, time of day, and health status. During exercise, HRV decreases as heart rate and exercise intensity increase. HRV also decreases during periods of mental stress.

HRV is regulated by the autonomic nervous system. Parasympathetic activity decreases heart rate and increases HRV, whereas sympathetic activity increases heart rate and decreases HRV.

HRV is used in the Ownzone, OwnIndex, and in OwnOptimizer features. It can also be monitored on its own using the running computer. If your HRV changes at a given running pace and heart rate, this may indicate a change in your training load and stress.

Cadence* is the number of times the foot with the stride sensor* hits the ground per minute.

Stride length* is the average length of one step. That is the distance between your right and left foot contacting the ground.

Running speed = 2 * stride length * cadence

There are two ways to run faster: moving your legs at a higher cadence or taking longer steps.

Elite long distance runners typically run with a high cadence of 85-95. On uphills, typical cadence values are lower. On downhills they are higher. Runners adjust stride length to gather speed: stride length increases as speed increases.

Yet one of the most common mistakes novice runners make is over-striding. The most efficient stride length is the natural one – the one that feels most comfortable. You will run faster in races by strengthening your leg muscles so they take you forward with a longer stride.

You should also work on maximizing cadence efficiency. Cadence does not progress easily, but if properly trained, you will be able to sustain it throughout your runs and maximize your performance. To develop cadence, the nerve-muscle connection needs to be trained - and reasonably frequently. A session of cadence training a week is a good start. Incorporate some cadence work into the rest of your week. During long easy runs, you could include some faster cadence every now and then.

When training for longer running events (½ Marathon, Marathon or longer), it may be helpful to monitor cadence. A low cadence at expected race pace can cause problems later in the event, as your legs tire. One way around this is to work on increasing leg speed at expected race pace. You can set your running computer to show pace and cadence. Try to shorten your stride and increase cadence while holding the same pace (set a narrow pace zone to give you audio feedback).You can aim to raise running cadence above the following:

This is a general guide only, taller runners will naturally have slightly lower cadences. Runners should also tune in to what feels comfortable for them personally.

A good way of improving stride length is to undertake specific strength work, like running hills, running in soft sand, or running up steps. A six-week training period including strength work should result in noticeable improvements in stride length, and if combined with some faster leg speed work (such as short strides at best 5km pace), noticeable improvements should be seen in overall speed, as well.

*Optional s3 stride sensor W.I.N.D. required.

R-R recording rate saves heartbeat intervals, i.e. intervals between successive heartbeats. This information is also shown as instantaneous heart rate in beats per minute in recorded samples.

When recording every single interval, extra systoles and artefacts can also be seen. We recommend using contact gel (ECG gel) to optimize contact between your skin and the transmitter. Readings interpreted as incorrect in the heart rate data can be adjusted and corrected with the software.

Running Index offers an easy way to monitor performance changes. Performance (how fast/easily you run at a given pace) is directly influenced by aerobic fitness (VO_2max) and exercise economy (how efficient your body is at running), and Running Index is a measurement of this influence. By recording your Running Index over time, you can monitor progress. Improvement means that running at a given pace requires less of an effort, or that your pace is faster at a given level of exertion. The Running Index feature calculates such improvements. Running Index also gives you daily information on your running performance level which may vary from day to day.

Benefits of Running Index:

Running Index is calculated during every exercise when heart rate and the stride sensor* signal is recorded, and when the following requirements apply:

Make sure that the stride sensor is calibrated. Calculation begins when you start recording the session. During the session, you may stop once at traffic lights, for example, without interrupting the calculation.

In the end, your running computer displays a Running Index value and stores the result in the File section. Compare your result to the table below. Using the software, you can monitor and analyze your progress in Running Index values against time and different running speeds. Or compare values from different exercise sessions and analyze them in the short and long term.

Short-term analysis

There may be some daily variation in the Running Indexes due to running circumstances e.g. surface, hills, wind, temperature.

Long-term analysis

The single Running Index values form a trend that predicts your success in running certain distances.

The following chart estimates the duration that a runner can achieve in certain distances when performing maximally. Use your long-term Running Index average in the interpretation of the chart. The prediction is best for those Running Index values that have been received at speed and running circumstances similar to the target performance.

*Optional s3 stride sensor W.I.N.D. required.

It is worth to remember that in addition to good Running Index, maximal running performance demands good preparation, optimal running conditions, speed endurance and guts. Training quantity and quality have an affect as well as natural talent.

** This is a sum of 2 or more exercises; maximum duration of a single exercise is 99 h 59 min 59 s. The maximum recording time can be shorter, if you record a large number of short exercises.

Recording doesn't automatically stop when the memory becomes full. Therefore, exercise time may be longer than recording time.