Dear Pat, thank you for your question. The normal range for stroke volume is 50-70 cc's and doesn't vary much with age.
Stroke volume refers to the amount of blood ejected from the heart with each heartbeat.
The only way to directly measure stroke volume is through a cardiac catheterization where the cardiac output can be directly measured with a catheter in the heart. You would be deathly ill if your stroke volume were 16, so I think that value refers to your VO2 max instead. I think you should check with your physician regarding this measurement. I hope you find this information useful. Information provided in the heart forum is for general purposes only.