Please help, I can't fail this!

Calculate the heart rate reserve for a 40-year-old with a resting heart rate of 75.
A. 80.5
B. 105
C. 115.5
D. 130.2


Respuesta :

Zla
Resting rate - maximum rate.

40 year old - 220 maximum rate
180 - resting rate 
180 - 75 = 
105 
B

The heart rate reserve is equal to the difference between maximum heart rate and resting heart rate. Maximum heart rate is usually calculated by:
Hmax = 220 - age
Hmax = 220 - 40 = 180
HRR = Hmax - Hrest
HRR = 180 - 75
= 105
The answer is B