The what and how of Running Index

If you’re looking to keep on top of your running performance you’ll find this feature a big help. Regular use over time allows you to see how efficient your running is. Your Running Index score is calculated automatically after every run, based on your heart rate and from the speed data collected via GPS or stride sensor. A higher reading indicates that you can run faster with less effort.

Running Index is available with the Polar V800, Polar M600, Polar M400, Polar Beat, RS400, RS800CX, RCX3, RC3GPS and RCX5.

 

What is Running Index?

Running Index gives you valuable information about your maximal aerobic running performance. The calculation is based on heart rate and speed data measured during a run. It's calculated every time you do a running exercise that's longer than 12 minutes, where heart rate is recorded and your speed remains above 6 km/h / 3.7 mph.

Why should I be interested in my Running Index?

Whether you’re training for a specific goal or just running to keep fit and healthy, seeing progress is usually what keeps us motivated. With the Running Index report in Flow web service you can easily monitor your progress and see how your running performance develops over time.

You may also find it interesting to compare your Running Index value to gender and age related aerobic fitness norms. At a population level, aerobic fitness declines with aging, and men generally speaking have better physical attributes for running than women. Comparing your Running Index value with others will give you an idea of your own running fitness level – whether you’re fitter than average in your age group, or if you have some work cut out for you.

How is Running Index calculated?

Calculation begins when you start recording and you have the necessary GPS or Stride sensors in use. The prerequisites for calculation are that your speed remains above 6 km/h and that the run lasts for at least 12 minutes. Although speed is a prerequisite for the calculation, the algorithm does however take natural, unavoidable pauses in your run into consideration. It allows you to stop running or slow down for a minute twice during training, in traffic lights, for example, without disturbing the calculation. In order to get reliable and therefore useful estimations on race times and your progress it’s essential to set your personal maximalThe highest number of heartbeats per minute (bpm) you can achieve in all-out effort. and resting heart rateThe lowest number of heartbeats per minute (bpm) at complete rest. values as accurately as possible in the Physical settings in Flow web service.

How do I analyze my Running Index?

Before you start analyzing your progress, make sure you have set your maximum heart rateThe highest number of heartbeats per minute (bpm) you can achieve in all-out effort. and resting heart rateThe lowest number of heartbeats per minute (bpm) at complete rest. values in the Flow web service to get as accurate analysis of your performance as possible.

Every time you do a running exercise, you get a numerical Running Index value. A higher value indicates better running performance, and changes in your Running Index average tells you whether you’re gaining or losing running fitness. You should bear in mind that the long term analysis of your Running Index in the Flow web service takes into account a weighted average of four weeks, with emphasis on the last two weeks. Variation on a day-to-day basis can be affected by all factors that have an effect on the relationship between heart rate and running speed. These factors can be environmental factors such as heat, altitude, air resistance, terrain, and running surface; external factors such as clothing, shoes, calibration of a stride sensor; and internal factors such as training status, mood or dehydration.

To compare your running fitness with people of the same age and gender, you can use the following chart.

Men

Age / Years

Very low

Low

Fair

Moderate

Good

Very good

Elite

20-24

< 32

32-37

38-43

44-50

51-56

57-62

> 62

25-29

< 31

31-35

36-42

43-48

49-53

54-59

> 59

30-34

< 29

29-34

35-40

41-45

46-51

52-56

> 56

35-39

< 28

28-32

33-38

39-43

44-48

49-54

> 54

40-44

< 26

26-31

32-35

36-41

42-46

47-51

> 51

45-49

< 25

25-29

30-34

35-39

40-43

44-48

> 48

50-54

< 24

24-27

28-32

33-36

37-41

42-46

> 46

55-59

< 22

22-26

27-30

31-34

35-39

40-43

> 43

60-65

< 21

21-24

25-28

29-32

33-36

37-40

> 40

Women

Age / Years

Very low

Low

Fair

Moderate

Good

Very good

Elite

20-24

< 27

27-31

32-36

37-41

42-46

47-51

> 51

25-29

< 26

26-30

31-35

36-40

41-44

45-49

> 49

30-34

< 25

25-29

30-33

34-37

38-42

43-46

> 46

35-39

< 24

24-27

28-31

32-35

36-40

41-44

> 44

40-44

< 22

22-25

26-29

30-33

34-37

38-41

> 41

45-49

< 21

21-23

24-27

28-31

32-35

36-38

> 38

50-54

< 19

19-22

23-25

26-29

30-32

33-36

> 36

55-59

< 18

18-20

21-23

24-27

28-30

31-33

> 33

60-65

< 16

16-18

19-21

22-24

25-27

28-30

> 30

The classification is based on a study by Shvartz & Reibold (1990). Laboratory measured VO2max values have been collected from adults in USA, Canada and 7 European countries.

Analyzing your progress in Flow web service

The Running Index report in Flow web service is a tool to help you monitor your long term Running Index development, and estimate your success in running for example 10K or a half marathon.

Each grey dot on the graph represents a Running Index value for a specific session on a specific day. The moving average line in blue demonstrates your Running Index trend, in other words your average Running Index, and this is what you should focus on when analyzing your progress – whether the trend on the graph is pointing up or down.

The progress chart shows your latest Running Index average and an estimate of your performance on certain distances based on that average. It also shows the progress you’ve made between the starting date of your chosen time period and where you are now. Individual sessions of the selected period are listed in the session list, where you can see your Running Index for a particular session.

How do I use Running Index in my training?

Running Index factors together maximal oxygen uptake (VO2max) and running economy and it’s a good predictor of race performance in endurance running. You can use it to predict how fast you could run, for example, a distance of 5K or 10K.

Although you can quite reliably predict your performance using Running Index, you should not forget the importance of other factors such as good preparation, optimal running conditions, and determination - we are all human after all.

Scientific background

Maximal aerobic running fitness is typically measured during a graded exercise test until the voluntary maximum is reached. Special equipment is used to measure oxygen uptake based on inhaled and exhaled air. During the graded exercise test, maximal oxygen uptake (VO2max) is reached when oxygen uptake no longer increases with increasing exercise intensity. Maximal aerobic running speed refers to the running speed at which VO2max occurs.

Running Index applies the essentially linear relationship between heart rate and oxygen uptake during increasing running speed at submaximal speeds. When both resting heart rate and maximal heart rate are known, maximal aerobic running performance can be estimated based on heart rate and speed measured during exercise.

The relationship between running speed and heart rate changes when you gain or lose fitness. When you gain fitness, your heart rate typically decreases at any given submaximal speed, and similarly when you lose fitness, your heart rate typically increases at any given submaximal speed. Running Index takes advantage of this well-known phenomenon and allows you to easily monitor changes in your running performance.

Running Index on Polar Beat mobile application

Running Index is available on the Polar Beat mobile application as an in-app purchase. To make the purchase in the AppStore, open Polar Beat application and go to Upgrades. You will also need a compatible Polar heart rate sensor. After a running session you'll see your Running Index in the training result.

Polar Beat gets the speed and distance using the phone's GPS. When using Polar Stride Sensor Bluetooth Smart to record speed and distance, make sure you select a sport setting in Beat that supports the stride sensor.

Polar Beat calculates Running Index during every training session where heart rate and GPS signals are recorded, and when:

  • Your running pace is at least 6 km/h / 3.7 mph or faster
  • Training duration is minimum of 12 minutes
  • Heart rate is above 30% of your HRRvalue.

 

Running Index on V800

Running Index is calculated during every training session when heart rate and the GPS function is on / Stride Sensor Bluetooth® Smart is in use, and when the following requirements apply:

  • Sport profile used is a running type sport (Running, Road Running, Trail running etc.)
  • Pace should be 6 km/h / 3.7 mph or faster and duration 12 minutes minimum.

Calculation begins when you start recording the session. Running Index in V800 takes the effect of terrain into account. At a given pace, running uphill is physiologically more stressful than running on a level surface, and running downhill is physiologically less stressful than running on a level surface. Please note that altitude data must be available for uphill and downhill to be taken into account.

Running Index on M400 / M600

Running Index is calculated during every training session when heart rate and the GPS function is on and when the following requirements apply:

  • Sport profile used is a running type sport (Running, Road Running, Trail running etc.)
  • Pace should be 6 km/h / 3.7 mph or faster and duration 12 minutes minimum.

Calculation begins when you start recording the session. During a session, you may stop twice at traffic lights, for example, without interrupting the calculation. After your session, the M400 / M600 displays a Running Index value and stores the result in the training summary.