The Garmin Premium Heart Rate Monitor (Soft Strap) is much like any soft fabric. In order to be at its best performance, it must be cleaned. Not washing the heart rate monitor (HRM) on a consistent basis can cause sweat and salt to build up on the strap. An increased build up of either can decrease the ability for the strap to report correct data.
The method of cleaning is determined by the markings on the strap (located on the strap next to the left hand skin contact patch):
Machine Washing (filled bucket with 40°):
For soft straps with a machine washing instructions, follow the recommended cleaning and care criteria for the heart rate monitor:
Hand Washing (image with a filled bucket with a hand entering the top):
For soft straps with a hand washing instructions, follow the recommended cleaning and care criteria for the heart rate monitor:
To prolong the life of the HRM, follow the recommended suggestions below.
The above recommendations can also be reviewed on the HRMcare document.
HRMcare document - http://static.garmincdn.com/pumac/HRMSS_Care_ML12.pdf