Altitude Mode

SpO2, peripheral capillary oxygen saturation, is an estimate of the amount of oxygen in the blood and measures the amount of oxygen-carrying hemoglobin in the blood. COROS watches calculate SpO2 mainly by emitting and absolving light passing through blood vessels. As the elevation increases, SpO2 will gradually decrease.

When the elevation is above 2500 meters, oxygen intake and blood oxygen saturation will decrease and may cause symptoms including acute altitude sickness and high-altitude pulmonary edema (HAPE). COROS measures SpO2, heart rate, elevation and other data to estimate altitude acclimation at certain altitude.

COROS development team successfully applied wrist-based SpO2 detection technology on watches and achieved accuracy comparable to medical fingertip measurement when remain stable at the end of 2017. However, SpO2 data provides limited assistance to climbers without applicable indications and suggestions including altitude sickness risk analysis, altitude acclimation evaluation, and activity intensity suggestions.

COROS partnered with a sport university and utilized their labs to simulate high altitude environments. After extensive data collection, research, and development for over a year, COROS was able to develop an Altitude Acclimation Evaluation System. Through applying this system, individual altitude acclimation analysis coupled with real time measurements can provide sound and practical acclimation assistance and guides for climbers. COROS Altitude Acclimation Evaluation System collects the SpO2 data and evaluates the altitude acclimation level for climbers when the elevation is above 2500 meters. Climbers are given more quantified and accurate info and under real time monitoring and notifications to effectively prevent altitude sickness.

Based on the indicated zones, Altitude Acclimation Index helps climbers plan out activities accordingly.

  • When Altitude Acclimation Index is between 0-60, climbers have low acclimation of current altitude. If remain in this zone for too long and have symptoms like headache, rapid heart rate, shortness of breath, chest tightness or purple discoloration on lips, it is recommended to descend. If no obvious discomfort, please focus on rest.
  • When Altitude Acclimation Index is between 61-80, climbers have medium acclimation of current altitude. If no obvious discomfort, climbers can perform certain activities to better adapt to current altitude. Please focus on rest if discomfort occurs.
  • When Altitude Acclimation Index is between 81-100, climbers have strong acclimation of current altitude. If remain in this zone with no obvious discomfort, expedition can resume.

In order to record accurate readings, please place the watch tightly against your wrist and next to the wrist bone. During the measurement, please keep your forearm horizontal and still.

When temperature is low, blood vessels will shrink and device may fail to detect SpO2 readings. When low temperature notification shows up during the measurement, please bring up the temperate of your wrist and resume the measurement.

If you still need help, please contact COROS support.