VO2 and max

[Justin23452]

can anyone explain this 2 me I mnot 100% sure about this.

VO2=(60mpb x 70mL/beat)
(6 mL O2/100 mL blood)
= 252 mL O2/min

Divided by 70kg, his resting VO2 is about 3.6 mK/kg/min. During maximal exercise this man has a heart rare of 180 bpm, a SV (Stroke Volume) of 115 mL/beat, and an oxygen extraction of 15 mL O2/100 mL blood.
SO hi mamimum VO2 is

VO2 max = (180 bmp x 115 mL/beat)
x (15 ml O2/100 mL/blood)
= 3,105 mL O2/min

This can be expressed in mL O2/kg/min by dividing bhy mans weight 70kg (154lbs)

3105 mL O2/min divided by 70kg= 44.4mL/kg/min

can anyone explain to me how they get there bottom numbers. And wtf is going on here. IM studying to become a PT and this is my 2nd day studying so I hope you guys can help me out with this.

 

[my big toe]

Which bottom numbers are you referring to? The total 3105 mL O2/min represents the amount of O2 that is used in one minute of exercise at MAX heart rate (180 beat/min). By dividing by the person's weight of 70kg, you get a number that is useful for comparison, since a larger person would have greater O2 requirement. So 44.4mL/kg/min means that person is using 44mL of O2 per kg of bodyweight every minute of exercise at max heart rate. The theory is that the more O2 that you can utilize, the more effieciently you oxidize fuels. Not sure if that helps.

 

[Justin23452]

Im wondering how you come up with (for this 1) 3,105 mL O2/min
VO2 max = (180 bmp x 115 mL/beat)
x (15 ml O2/100 mL/blood)
= 3,105 mL O2/min

And for this one 252 nL O2/min
VO2=(60mpb x 70mL/beat)
(6 mL O2/100 mL blood)
= 252 mL O2/min

because when u X 60bpb with 70mL/beat you get 4,200 ml a min correct? what or how do u add or workout 6 ml O2/100 mL blood with the 4,200 and get 252 Ml O2/min thats what im not so sure about.

and thanks for your reply

 

[my big toe]

Yeah, the second one is a measure of the total volume of oxygen used at 1/3 the heartrate or MAX HR. So the the steps are:
60bpm * 70ml = 4200 mL of total blood Pumped per minute (not O2 used per minute).
Then you multiply by 6, since there is 6mL of O2 used for every 100 mL of blood pumped: 4200 * 6 = 25,200 ,
then 25,200/100 = 252 mL of O2 used per minute.

The first equation is exactly the same except the HR is higher (180), and more O2 (15mL) used per 100 mL.

 

[Justin23452]

ahhhh alright thank you very much.