How the heart rate measurement works

The principle of pulse measurement on the wrist is simple: Light is irradiated onto the skin and an optical sensor measures the reflection of the light. The blood flow changes during the beat of the heart and thereby also the reflected quantity of light. The heart rate is recorded in this way. For the measurement to function optimally, the direct contact with the skin is essential.

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Faster GPS fix

For the integration of the GPS measurement, attention was paid to the highest accuracy with the lowest possible power consumption. In order to obtain a fast GPS signal, the GSP satellite data can be loaded beforehand via the SIGMA LINK app or the DATA CENTER. Thus, the training can begin quickly.

Smart connectivity

In the SIGMA LINK app, you will also get a detailed training evaluation on the move. The training data can also be transferred to the DATA CENTER or vice versa via SIGMA CLOUD. From both platforms, you can also share your data in social media or training portals.

In addition to the functions of the SIGMA LINK app, the DATA CENTER can be used to process the training data, as well as to develop in-depth analyses.

The issue of data security is taken very seriously by SIGMA SPORT. The mobile apps do not require any user registration and your data is only stored locally on the terminal device. If you want to use the convenience of cloud-based data storage, the SIGMA CLOUD provides secure storage of data on European servers. Your data will, of course, not be passed on to third parties.

Acceleration sensor

The current distance is determined by GPS. If you want to do a training session without GPS, the iD.RUN HR can also calculate the distance using an acceleration sensor.

Step analysis
The cadence and step length are determined by means of an acceleration sensor. Conclusions can be arrived at with it, for example, on the running technique and the fatigue condition.

The integrated acceleration sensor is continuously calibrated during a training session. When you turn off the GPS (e.g. on the treadmill), the speed and distance can be determined by the sensor.

Data exchange via NFC

NFC means Near Field Communication and is an international transmission standard for the wireless exchange of data over very short distances. The transfer via NFC is only possible by Android smart phones. The smart phone is placed on the iD.RUN HR and the data exchange already starts within the opened SIGMA LINK app.

Long running time

The integrated battery lasts up to 14 days depending on usage. The maximum running time is reached in stand-by mode, and up to 6 hours are possible in the training mode. The iD.RUN HR is fully charged again within a short time using the included USB cable.


14 days
in stand-by mode
6 hours
im training mode