When sampling venous blood from a working muscle, lactate concentration can be 10-12 mmol/L, but arterial blood concentration drops to 4 mmol/L within one complete circulation due to lactate-pyruvate conversions.

“uh lactate uh very high in the Venus effin of a working muscle I'm going to just make up some numbers here 10 to 12 and uh at the same time we since we had arterial sampling versus femal venous sampling when the blood goes around the body not even one complete passage it's down to 4 molar so there are lactate pyate conversions happening in the blood in part by the red blood cells and in part by the lung parenchima cuz all the blood goes through the lungs”