Question

1. Anna is a 52-year old female, who is 5’4”, and weights 130lbs. You tested Anna’s 1-mile outdoor walk, and determined she was able to complete 1-mile in 12:45, with a post-walk HR of 147 bpm. What are each of the following:
   1. Absolute VO₂ max
   2. Relative VO₂ max
   3. Absolute and Relative VO₂ at 70%
   4. MET level at 70%
   5. Calorie expenditure per minute at 70%

Answer 1

Ans: The test using 1-mile walk is the Rockport Fitness Walking Test (RFWT) and is used to calculate VO2 max by formula:

Absolute VO2 max = 132.853 - (0.0769 x W) - (0.3877 x A) + (6.315 x G) - (3.2649 x T) - (0.1565 x H)

W = Weight (in lbs), A = Age (in years), G = Gender factor, G=0 for females and G=1 for males, T= Time to complete 1-mile walk (in minutes),

H= Number of heart beats in 10 seconds at the end of 1-mile walk

So, VO2 max = 132.853 - (0.0769 x 130) - (0.3877 x 52) + (6.315 x 0) - {3.2649 x [12 + (45/60)]} - {0.1565 x [147 x (10/60)]}

= 132.853 - 9.997 - 20.160 + 0 - (3.2649 x 12.75) - (0.1565 x 24.5)

= 102.696 - 41.628 - 3.834

VO2 max = 57.234 mL/kg/min

Therefore, Relative VO2 max = 57.234 mL/kg/min

(a) Absolute VO2 max = 57.234 x 52 = 2976.168 mL/min

(b) Relative VO2 max = 57.234 mL/kg/min

(c) Absolute VO2 at 70% = 2976.168 x (70/100) = 2083.3176 mL/min

and Relative VO2 at 70% = 57.234 x (70/100) = 40.0638 mL/kg/min

(d) MET at 70% = Relative VO2 max at 70% / 3.5

= 40.0638/ 3.5 = 11.4468 ml/m

(e) Calorie expenditure per minute at 70% = Absolute VO2 in L/min x 5

= (2976.168/1000) x 5

= 14.8808 kcals/min