Answer :
To achieve 60% VO2R for a 122-lb client at 4.5 mph, the required treadmill % grade is approximately 6%.
To determine the treadmill % grade required to achieve 60% VO2R at a running speed of 4.5 mph for a client with a 13-MET max, we need to follow these steps:
Convert METs to VO2: Since 1 MET = 3.5 mL/kg/min, the client's max VO2 is 13 METs * 3.5 mL/kg/min = 45.5 mL/kg/min.
Calculate VO2 Reserve (VO2R): VO2R = VO2max - VO2rest. Assuming VO2rest is 3.5 mL/kg/min, VO2R = 45.5 - 3.5 = 42 mL/kg/min.
Determine Target VO2R: Target VO2R = 60% of VO2R = 0.60 * 42 = 25.2 mL/kg/min.
Add Resting VO2: Desired VO2 = 25.2 mL/kg/min + 3.5 mL/kg/min = 28.7 mL/kg/min.
Use Treadmill Equation to Find % Grade:
The treadmill % grade equation is: VO2 = (Speed * 0.1) + (Grade * Speed * 1.8) + 3.5.
Rearranging for Grade:
28.7 = (4.5 * 26.8 * 0.1) + (Grade * 4.5 * 26.8 * 1.8) + 3.5
28.7 - 3.5 - 12.06 = 4.5 * 26.8 * 1.8 * Grade
13.14 = 216.9 * Grade
Grade = 13.14 / 216.9 ≈ 0.06 (or 6%)
So, the required treadmill % grade to achieve the desired intensity is approximately 6%.
