Average Smo2 and tHb in the Lap+Session messages an array

Update: I wonder if the total_hemoglobin and saturated_hemoglobin summary fields in the Lap and Session messages are arrays because it's possible for athletes to wear multiple sensors simultaneously. I.e. one on each thigh. So each sensor is a different element in the array. If that's the case, then why are the SmO2 and tHb fields in the Record message also arrays?

The total_hemoglobin and saturated_hemoglobin summary fields are pretty old, and I was not able to dig up any history on them. More than likely the fields were added to the FIT Profile during development of the ANT+ MO2 Device Profile and before there was a clear intent for them. If the fields were meant to hold the data from multiple sensors, then the corresponding fields in the Record message should have been arrays too. 

The best practice for Garmin devices is to use the manufacturer's CIQ data field(s) instead of the native integration. That is the only option for Edge bike computers since there is no native integration for MO2 sensors. For other device manufacturers that support MO2 sensors, the native values in the FIT file are typically the only option.

Oof, this is really messy. I have 7 sample FIT files that contain SmO2 data, and there are 5 different ways that they're being stored. With the mix of sensor manufacturers and and watch/bike computer manufacturers this could benefit from better definition in the FIT Profile so that it's standardized across all of those manufacturers.