cold legs muscles?

hey all, when im on my exercise bike the back of my legs occasionally get a cold feeling in them? im not exercising in a cold room or outside.
any thoughts would be great, thanks
tom
 
I experience something similar when swimming. Does this happen after any particular duration of work or intensity of work?
QC
 
When I trained in MTBing I sometimes experienced the same feeling, though I don't know why it happens.
 
Back
Top