When I'm riding rollers/trainer and maintaining a given
HR (say 141 ) if I'm on the hoods/dropouts it holds
fairly stable for a given RPM. If however I sit up
I notice an almost immediate increase in HR,
of about 4 - 10 BPM.
I would have thought that being upright would
give a more open diaphram, easier breathing etc.
and not effect HR.
I'd chalk it upto an increase due to the movement
of sitting up but it seems to increase and stay at
an elevate level.
Anyone else notice anything like this?