What can cause higher error percentages in Firstbeat Sports Live app data?

Some factors that might cause higher error percentages in Firstbeat Sports Live app data are listed below.

To avoid problems, please instruct your athletes to properly wear and maintain the Firstbeat Sports Sensors (Sensors) and HR straps.

Artifact tail (i.e. incorrect RR-i values at the end of the data)

If the Sensor is left attached to the HR strap there might be an extra HR artifact tail recorded that can’t be automatically removed. High error % at the end of the recording can increase the total average error % which then causes the server to fully reject the data.

• Remove at least one Sensor pin from the HR strap to help the Sensor automatically stop recording. Or, detach the Sensor completely from the strap.
• Attach the Sensor and rinse the strap after each use. Don't just throw the worn, sweaty strap with the Sensor still attached into a sports bag. Check the maintenance guidance for more info.

Wearing the heart rate strap

Wearing both the Sensor and HR strap properly is important to ensure good data quality and successful measurements. Common problems include:

• Strap and skin are not moist enough for a good signal detection. Dry HR straps and skin conduct electric signals poorly. For this reason, it is important to moisten the HR strap and dampen the skin under the HR strap before training.
• Make it snug! The HR strap should sit firmly so that it doesn’t move during activity.
  Check before starting that the strap is tight enough. The strap might loosen while training so try tightening the strap occasionally if possible.
• Strap placement is wrong (e.g., too low). Try moving the strap higher and, where women are concerned, under the sports bra if possible. Check the guidance on how to wear the Sports Sensor for more info.
• Some sport types with lots of arm and upper body movements might be more prone to errors. For example, CrossFit, tennis, and handball. In these cases, tightening the HR strap properly is vital.

Like all things, the HR straps wear out over time. When under heavy use, it might wear out sooner. If you need to acquire new straps, please contact your Firstbeat Sports sales representative.

Attaching the Sensor to the HR strap

Attach the Sensor to the Strap carefully. Make sure that both pins are securely attached to the strap and the Sensor is not attached upside down. Common problems, and solutions:

• One of the two pins is loose. Make sure both pins are securely attached.
• The Sensor is worn upside down i.e. the Firstbeat text is upside down.
• The Sensor is not properly attached to the HR strap, i.e. it does not snap in properly. Try replacing the strap to check that both of the pins snap in well.
• There are athletes with big upper body muscles and/or a rounded chest. For them, the Sensor might more easily detach. We have observed that there are minor differences in how tight the Sensor attachment connection is on different HR straps. If you have problems with the Sensor popping out for specific athletes, you could try to give them a strap that has a tighter attachment.

Clothing

Some (dry) shirts can create lots of electricity. The texture and the material of the shirt can affect this. Texture and material of some sports bras can also have the same effect.

• Try if wearing a different type of shirt helps.

How to investigate what is causing high error rate or measurements to fail

• Try using a different HR strap (rules out HR strap as the issue)
• Try with a different Sensor (rules out Sensor as the issue)
• Try to replicate the problem in a different location (i.e. move from gym to outdoors) ⟶ This will help identity/rule out a potential environmental factor causing the problem

If the error percentages remain high despite considering all of the above-mentioned issues, the Sports Sensor might be broken. In this case, please fill in the faulty device form to begin the replacement process.