{HEAD ~ One or more additional sensors} that do not measure {TAIL ~ hydration level} of the user can be coupled to a hydration sensing element to determine the amount of fluid consumption for the user in different conditions 
not measure
{ HEAD ~ One or more additional sensors } that do not measure { TAIL ~ hydration level } of the user can be coupled to a hydration sensing element to determine the amount of fluid consumption for the user in different conditions
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH