dteubner

In your experiment it is very unlikely that your CO2 was at all high - it may even have been a bit low.

The sensation of dyspnoea (shortness of breath) with exercise is not related to an elevation in CO2 (hypercarbia), it is not well understood but relates to a whole host of factors.

Dyspnoea post exercise is also not related to hypercarbia.

If you do vigorous exercise and then hold your breath for a few seconds, your CO2 will not rise much at all.

Genesis's experiment, on the other hand, almost certainly did cause hypercarbia and he was significantly incapacitated even on a couch with no task loading.

The main point about a BOV is that if your CO2 rises moderately high it will be almost impossible to hold your breath long enough to swap to a different gas source, which might take longer than you hope because of loss of coordination.

Dave T